BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether...BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether PSIS can lead to liver cirrhosis.CASE SUMMARY This paper reported a case of liver cirrhosis of unknown origin.The patient was admitted to Beijing Ditan Hospital Affiliated to Capital Medical University in November 2023.The diagnosis of PSIS complicated with liver cirrhosis was established after a series of blood tests and pituitary magnetic resonance imaging examination.CONCLUSION We also reviewed the literature from both domestic and international sources to deepen the clinical understanding of PSIS in conjunction with liver cirrhosis among medical practitioners.展开更多
The aim of this study was to design a cage-like radiotherapy system(CRTS)to further promote the clinical application of noncoplanar radiotherapy.The CRTS comprises two stands,two O-rings,several arc girders,an X-ray h...The aim of this study was to design a cage-like radiotherapy system(CRTS)to further promote the clinical application of noncoplanar radiotherapy.The CRTS comprises two stands,two O-rings,several arc girders,an X-ray head,an imaging subsystem,and a treatment couch.The X-ray head rotates with O-rings around the patient’s body and slides along the arc girder.Compared with the C-arm linear accelerator(C-Linac),the clinically available spatial irradiation angle ranges(SIARs)of the CRTS for the head,chest,and abdomen were 33%,63.6%,and 62.6%larger,respectively.Moreover,according to a preliminary planning comparison based on the dose distribution simulation method,the CRTS achieved much better protection of normal tissue than the C-Linac.Furthermore,the CRTS enabled accurate noncoplanar irradiation without movement of the body being irradiated,allowed automatic control of the movements of different parts without risk of collisions,and provided continuous radiation over an angle that considerably exceeded a full turn.These advantages make CRTS very promising for noncoplanar radiotherapy.展开更多
To investigate the effects of individualised treatment with peginterferon alpha-2a(40 kD)plus ribavirin in Chinese patients with CHC.Methods Total of 297 consecutive Chinese patients were enrolled,including 250 nave c...To investigate the effects of individualised treatment with peginterferon alpha-2a(40 kD)plus ribavirin in Chinese patients with CHC.Methods Total of 297 consecutive Chinese patients were enrolled,including 250 nave cases and 47 cases who were previously treated.Treatment duration was determined according to viral genotypes,prior treatment history and viral responses at week 4,12 and 24.Results Totally,235 patients(79.1%)completed treatment and 186(87.3%)achieved SVR.And 219 out of 289(75.8%)patients achieved HCV RNA negative at week 4(RVR)and 259 of 276(93.8%)at week 12.Among the 164 patients with RVR who completed follow-up,158(96.3%)achieved SVR.Patients with RVR had lower baseline viral loads than patients without RVR(P=0.034).The positive predictive value(PPV)of RVR for SVR was 90.7%(OR 2.10 vs.non-RVR,95%CI:0.50-8.7).Similar outcomes were observed among patients with HCV undetectable at week 12.Conclusions Viral suppression by week 4 is associated with a high rate of treatment success in treatment nave and experienced patients receiving individualized CHC therapy.展开更多
Background: Recent studies reported that patients with coronavirus disease-2019(COVID-19) might have liver injury. However, few data on the combined analysis and change patterns of alanine aminotransferase(ALT), aspar...Background: Recent studies reported that patients with coronavirus disease-2019(COVID-19) might have liver injury. However, few data on the combined analysis and change patterns of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and total bilirubin(TBil) have been shown.Methods: This is a single-center retrospective study. A total of 105 adult patients hospitalized for confirmed COVID-19 in Beijing Ditan Hospital between January 12, and March 17, 2020 were included, and divided into mild group(n=79) and severe group(n=26). We compared liver functional test results between the two groups. Category of ALT change during the disease course was also examined.Results: 56.2%(59/105) of the patients had unnormal ALT, AST, or total TBil throughout the course of the disease, but in 91.4%(96/105) cases the level of ALT, AST or TBil ≤3 fold of the upper limit of normal reference range(ULN). The overall distribution of ALT, AST, and TBil were all significantly difference between mild and severe group(P<0.05). The percentage of the patients with elevated both ALT and AST was 12.7%(10/79) in mild cases vs. 46.2%(12/26) in severe cases(P=0.001). 34.6%(9/26) severe group patients started to have abnormal ALT after admission, and 73.3%(77/105) of all patients had normal ALT before discharge.Conclusions: Elevated liver function index is very common in patients with COVID-19 infection, and the level were less than 3×ULN, but most are reversible. The abnormality of 2 or more indexes is low in the patients with COVID-19, but it is more likely to occur in the severe group.展开更多
BACKGROUND This case series investigated the clinical manifestations,diagnoses,and treatment of cerebral abscesses caused by Streptococcus anginosus.We retrospectively analyzed the clinical characteristics and outcome...BACKGROUND This case series investigated the clinical manifestations,diagnoses,and treatment of cerebral abscesses caused by Streptococcus anginosus.We retrospectively analyzed the clinical characteristics and outcomes of three cases of cerebral abscesses caused by Streptococcus anginosus and conducted a comprehensive review of relevant literature.CASE SUMMARY Case 1 presented with a history of left otitis media and exhibited high fever,confusion,and vomiting as primary symptoms.Postoperative pus culture indicated a brain abscess caused by Streptococcus constellatus infection.Case 2 experienced dizziness for two days as the primary symptom.Postoperative pus culture suggested an intermediate streptococcal brain abscess.Case 3:Enhanced head magnetic resonance imaging(MRI)and diffusion-weighted imaging revealed occupancy of the left temporal lobe,initially suspected to be a metastatic tumor.However,a postoperative pus culture confirmed the presence of a brain abscess caused by Streptococcus anginosus infection.The three cases presented in this case series were all patients with community-acquired brain abscesses resulting from angina caused by Streptococcus group infection.All three patients demonstrated sensitivity to penicillin,ceftriaxone,vancomycin,linezolid,chloramphenicol,and levofloxacin.Successful treatment was achieved through stereotaxic puncture,drainage,and ceftriaxone administration with a six-week course of antibiotics.CONCLUSION Preoperative enhanced head MRI plays a critical role in distinguishing brain tumors from abscesses.Selecting the correct early diagnostic methods for brain abscesses and providing timely intervention are very important.This case series was in accordance with the CARE guidelines.展开更多
Hepatitis B virus(HBV)infection plays an important role in the occurrence and development of hepatocellular carcinoma(HCC),and the rate of HBV infection in liver cancer patients in China is as high as 92.05%.Due to lo...Hepatitis B virus(HBV)infection plays an important role in the occurrence and development of hepatocellular carcinoma(HCC),and the rate of HBV infection in liver cancer patients in China is as high as 92.05%.Due to long-term exposure to chronic antigens from the gut,the liver needs to maintain a certain level of immune tolerance,both to avoid severe inflammation caused by non-pathogenic antigens and to maintain the possibility of rapid and violent responses to infection and tumors.Therefore,HBV infection interacts with the tumor microenvironment(TME)through a highly complex and intertwined signaling pathway,which results in a special TME in HCC.Due to changes in the TME,tumor cells can evade immune surveillance by inhibiting tumor-specific T cell function through cytotoxic T-lymphocy-associated protein-4(CTLA-4)and programmed cell death 1(PD-1)/programmed cell death ligand 1(PD-L1).Interferons,as a class of immune factors with strong biological activity,can improve the TME of HBV-HCC through various pathways.In recent years,the systematic treatment of HCC has gradually come out of the dilemma.In addition to the continuous emergence of new multi-target anti-vascular tyrosine kinase inhibitor drugs,immune checkpoint inhibitors have opened up a new avenue for the systematic treatment of HCC.At present,immunotherapy based on PD-1/L1 inhibitors has gradually become a new direction of systematic treatment for HCC,and the disease charac-teristics of patients included in global clinical studies are different from those of Chinese patients.Therefore,whether a group of HCC patients with HBV background and poor prognosis in China can also benefit from immunotherapy is an issue of wide concern.This review aims to elucidate the advances of immuno-therapy for HBV related HCC patients with regard to:(1)Immunotherapy based on interferons;(2)Immunotherapy based on PD-1/L1 inhibitors;(3)Immunotherapy based on CTLA4 inhibitors;(4)Adoptive cell transfer;(5)Combination immunotherapy strategy;and(6)Shortcomings of immunotherapy.展开更多
AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, ...AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, who were treatment-naive, with a serum HBs Ag level < 100 IU/m L and an undetectable hepatitis B virus(HBV) DNA level(< 100 IU/m L). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBs Ag, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen(65.0%) of 20 treated patients achieved HBs Ag loss, 12 of whom achieved HBs Ag seroconversion. Mean HBs Ag level in treated patients decreased to 6.69 ± 13.04 IU/m L after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/m L. Serum HBV DNA level remained undetectable(< 100 IU/m L) in all treated patients during the study. HBs Ag level of the control group decreased from 25.72 ± 25.58 IU/m L at baseline to 17.11 ± 21.62 IU/m L at week 96(P = 0.108). In the control group, no patient experienced HBs Ag loss/seroconversion, and two(5.0%) developed HBV reactivation.CONCLUSION: IFN treatment results in HBs Ag loss and seroconversion in a considerable proportion of inactive HBs Ag carriers with low HBs Ag concentrations.展开更多
BACKGROUND: The availability of novel direct-acting antivirals (DAAs) represents a new era of curative hepatitis C virus (HCV) treatment, with over 95% of patients infected with HCV genotype 1 achieving sustained viro...BACKGROUND: The availability of novel direct-acting antivirals (DAAs) represents a new era of curative hepatitis C virus (HCV) treatment, with over 95% of patients infected with HCV genotype 1 achieving sustained virological response (SVR). Nevertheless, the majority of patients globally are unable to access these treatments because of cost and infrastructure constraints and, thus, remain untreated and uncured. DATA SOURCE: Relevant articles of peginterferon (PegIFN)-based treatments in HCV and sofosbuvir-based treatments, simeprevir, daclatasvir/asunaprevir, ritonavir-boosted paritaprevir/ombitasvir/dasabuvir, and grazoprevir/elbasvir, were searched in PubMed database, including general population and special population. RESULTS: PegIFN in combination with ribavirin remains an important and relevant option for some patients, achieving SVR rates of up to 79% in genotype 1 and 89% in genotype 2 or 3 infections, which increases for patients with favorable IL28B genotypes. Triple therapy of DAA plus PegIFN/ribavirin is effective in treating difficult-to-cure patients infected with HCV genotype 3 or with resistance-associated variants. Owing to its long history in HCV management, the efficacy, tolerability and long-term outcomes associated with PegIFN alfa-2a are well established and have been validated in large-scale studies and in clinical practice for many populations. Furthermore, emerging data show that IFN-induced SVR is associated with lower incidences of hepatocellular carcinoma compared with DAAs. On the contrary, novel DAAs have yet to be studied in special populations, and long-term outcomes, particularly tumor development and recurrence in patients with cirrhosis and/or hepatocellular carcinoma, and reactivation of HBV in dually infected patients, are still unclear. CONCLUSION: In this interferon-free era, PegIFN-based regimens remain a safe and effective option for selected HCV patients.展开更多
Due to the reservoir heterogeneity and the stress shadow effect, multiple hydraulic fractures within one fracturing segment cannot be initiated simultaneously and propagate evenly, which will cause a low effectiveness...Due to the reservoir heterogeneity and the stress shadow effect, multiple hydraulic fractures within one fracturing segment cannot be initiated simultaneously and propagate evenly, which will cause a low effectiveness of reservoir stimulation. Temporary plugging and diverting fracturing(TPDF) is considered to be a potential uniform-stimulation method for creating multiple fractures simultaneously in the oilfield. However, the multi-fracture propagation morphology during TPDF is not clear now. The purpose of this study is to quantitatively investigate the multi-fracture propagation morphology during TPDF through true tri-axial fracturing experiments and CT scanning. Critical parameters such as fracture spacing, number of perforation clusters, the viscosity of fracturing fluid, and the in-situ stress have been investigated. The fracture geometry before and after diversion have been quantitively analyzed based on the two-dimensional CT slices and three-dimensional reconstruction method. The main conclusions are as follows:(1) When injecting the high viscosity fluid or perforating at the location with low in-situ stress, multiple hydraulic fractures would simultaneously propagate. Otherwise, only one hydraulic fracture was created during the initial fracturing stage(IFS) for most tests.(2) The perforation cluster effectiveness(PCE) has increased from 26.62% during the IFS to 88.86% after using diverters.(3) The diverted fracture volume has no apparent correlation with the pressure peak and peak frequency during the diversion fracturing stage(DFS) but is positively correlated with water-work.(4) Four types of plugging behavior in shale could be controlled by adjusting the diverter recipe and diverter injection time, and the plugging behavior includes plugging the natural fracture in the wellbore, plugging the previous hydraulic fractures, plugging the fracture tip and plugging the bedding.展开更多
Intra-stage multi-cluster temporary plugging and diverting fracturing(ITPF)is one of the fastest-growing techniques to obtain uniform reservoir stimulation in shale gas reservoirs.However,propagation geometries of mul...Intra-stage multi-cluster temporary plugging and diverting fracturing(ITPF)is one of the fastest-growing techniques to obtain uniform reservoir stimulation in shale gas reservoirs.However,propagation geometries of multiple fractures during ITPF are not clear due that the existing numerical models cannot capture the effects of perforation plugging.In this paper,a new three-dimensional FEM based on CZM was developed to investigate multiple planar fracture propagation considering perforation plugging during ITPF.Meanwhile,the fluid pipe element and its subroutine were first developed to realize the flux partitioning before or after perforation plugging.The results showed that the perforation plugging changed the original distribution of the number of perforations in each fracture,thus changing the flux partitioning after perforation plugging,which could eliminate the effect of stress interference between multiple fractures and promote a uniform fluid distribution.The standard deviation of fluid distribution in the perforation plugging case was only 8.48%of that in the non-diversion case.Furthermore,critical plugging parameters have been investigated quantitatively.Specifically,injecting more diverters will create a higher fluid pressure rise in the wellbore,which will increase the risk of wellbore integrity.Comprehensively considering pressure rise and fluid distribution,the number of diverters should be 50%of the total number of perforations(N_(pt)),whose standard deviation of fluid distribution of multiple fractures was lower than those in the cases of injecting 10%N_(pt),30%N_(pt)and 70%N_(pt).The diverters should be injected at an appropriate timing,i.e.40%or 50%of the total fracturing time(tft),whose standard deviation of the fluid distribution was only about 20%of standard deviations in the cases of injecting at20%tftor 70%tft.A single injection with all diverters can maintain high bottom-hole pressure for a longer period and promote a more uniform fluid distribution.The standard deviation of the fluid distribution in the case of a single injection was 43.62%-55.41%of the other cases with multiple injection times.This study provides a meaningful perspective and some optimal plugging parameters on the field design during IPTF.展开更多
Background Uncertainty remains regarding the association between body mass index(BMI)and the risk of bleeding in patients with non-valvular atrial fibrillation(NVAF).We aimed to investigate the association between BMI...Background Uncertainty remains regarding the association between body mass index(BMI)and the risk of bleeding in patients with non-valvular atrial fibrillation(NVAF).We aimed to investigate the association between BMI and the risk of bleeding in elderly NVAF patients taking dabigatran.Methods A total of 509 elderly NVAF patients,who were being treated at twelve centers in China from February 2015 to December 2017 and taking dabigatran,were analyzed.The exposure and outcome variables were BMI at baseline and bleeding events within the subsequent six months,respectively.Cox proportional hazards regression analysis was used to evaluate the association between BMI and the risk of bleeding.Moreover,the Cox proportional hazards regression with cubic spline functions and smooth curve fitting was conducted.Results During the six-month follow-up,50 participants experienced bleeding.Every 1 kg/m^2 increase in BMI was associated with a 12%increased risk of bleeding(P=0.021).Compared to those with BMI values in Tertile 1(<22.5 kg/m^2),the adjusted hazard ratio(HR)of bleeding for participants in Tertile 2(22.5–25.3 kg/m^2)and Tertile 3(>25.3 kg/m^2)were 2.71(95%CI:1.02–7.17)and 3.5(95%CI:1.21–8.70),respectively.The Ptrend-value was significant in all models.The adjusted smooth curve showed a linear association between BMI and bleeding.None of the stratified variables showed significant effect modification on the association between BMI and bleeding(Pinteraction>0.05).Conclusions BMI was significantly and positively associated with the risk of bleeding in elderly NVAF patients treated with dabigatran.展开更多
Saliva and blood were collected from two patients who had not received post exposure prophylaxis in the cities of Wenzhou and Xinning respectively. Both patients were confirmed as positive for rabies by detection of r...Saliva and blood were collected from two patients who had not received post exposure prophylaxis in the cities of Wenzhou and Xinning respectively. Both patients were confirmed as positive for rabies by detection of rabies virus specific nucleoprotein antibodies in the sera by Western Blot. However, rabies virus specific RNA was only identified in the saliva collected from the patient in Wenzhou. Furthermore, the isolate Zhejiang Wz0 (H) was obtained by inoculating one-day-old suckling mice. Both nucleoprotein (N) and glycoprotein (G) genes from the isolate were amplified by RT-PCR and sequenced. Phylogenetic analysis indicated that the isolate belonged to classic rabies virus, and shared a higher homology with the street viruses from dogs in the main endemic areas in China and the street virus from dogs in Indonesia than with other known strains. Further comparison of the deduced amino acid sequences between the isolate and the vaccine strains used in China showed that the virus had a higher level of homology with the vaccine strain CTN than with the other vaccine strains (3aG, PV, PM and ERA). In particular, amino acid residues substitutions located in antigenic site Ⅲ in the G protein, which could react with the neutralizing antibodies, were observed. These results suggested that the virus belonged to the classic rabies virus, and both N and G genes diverged from the current vaccine strains used in China at either the nucleotide or the amino acid level.展开更多
Fracture propagation is affected by multi-metal-veins formed by geological diagenesis in shale during the hydraulic fracturing.However,the influence of multi-metal-veins on fractures propagation remains unclear.To sol...Fracture propagation is affected by multi-metal-veins formed by geological diagenesis in shale during the hydraulic fracturing.However,the influence of multi-metal-veins on fractures propagation remains unclear.To solve the problem,based on the semi-circle bending(SCB)test and the extended finite element(XFEM)theory,the interaction between multi-metal-veins and fractures is investigated.The experimental results reveal that the fractures usually deflect at the upper or lower interfaces between metal veins and rocks(e.g.the specimen S-2),which is different from the propagation behavior of fractures in calcite veins.Meanwhile,the fracture toughness of the specimen S-1 is 24.40%higher than that of the specimen S-2,indicating that the increasing of total thickness of multiple metal veins in-creases the resistance to the fracture vertical propagation.The simulation results show that the increasing of the number,total thickness of veins,the modulus difference between veins and rock,the approach angle and the notch angle all increase the resistance of the fracture passing through metal veins.The maximum deviation distance(Dmax)of the fracture decreases with the number of veins,while thickness combination types of metal veins do not affect Dmax.The reduction of the notch angle leads to the more tortuous fracture propagation path.Finally,we propose a new comprehensive fracture network pattern.Fracture networks are divided into two categories,including orthogonal fracture networks and sub-orthogonal fracture networks,and then divided into six sub-categories further.The research results will provide reference for hydraulic fracturing of shale reservoirs containing multi-metal-veins.展开更多
Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation bet...Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation between average dispersion measure(■)and dispersion measure difference(ΔDM)of known pulsars in GCs is lgΔDM∝1.52lg■.The sensitivity could be the key to finding more pulsars.As a result,several years after the construction of a large radio telescope facility,the number of known GC pulsars will likely be increased accordingly.We suggest that currently GCs in the southern hemisphere could have higher possibilities for finding new pulsars.展开更多
This paper presents a new measurement system based on integration method that can provide all-weather dependability and higher precision for the measurement of FAST's feed support system.The measurement system con...This paper presents a new measurement system based on integration method that can provide all-weather dependability and higher precision for the measurement of FAST's feed support system.The measurement system consists of three types of measuring equipments,and a processing software with the core data fusion algorithm.The Strapdown Inertial Navigation System(SINS)can autonomously measure the position,speed and attitude of the carrier.Its own shortcoming is that the measurement data diverge rapidly over time.SINS must combine the Global Positioning System(GPS)and the Total Station(TS)to obtain high-precision measurement data.The Kalman filtering algorithm is adopted for the integration measurement system,which is an optimal algorithm to estimate the measurement errors.A series of tests are carried out to evaluate the performance.For the feed cabin,the maximum RMS of the position is 14.56 mm,the maximum RMS of the attitude is 0.095,these values are less than 15 mm and 0.1°as the precision for measuring the feed cabin.For the Stewart manipulator,the maximum RMS of the position is 2.99 mm,the maximum RMS of the attitude is 0.093°,these values are less than 3 mm and 0.1°as the precision for measuring the Stewart manipulator.As a result,the new measurement meets the requirement of measurement precision for FAST's feed support system.展开更多
BACKGROUND Ultrasound is a vital tool for the diagnosis and management of colorectal cancer(CRC).Contrast-enhanced ultrasound(CEUS)is a non-invasive,safe,and cost-effective method for evaluating tumour blood vessels,t...BACKGROUND Ultrasound is a vital tool for the diagnosis and management of colorectal cancer(CRC).Contrast-enhanced ultrasound(CEUS)is a non-invasive,safe,and cost-effective method for evaluating tumour blood vessels,that play a crucial role in tumour growth and progression.AIM To explore CEUS’s role in the quantitative evaluation of CRC blood vessels and their correlation with angiogenesis markers and prognosis.METHODS This study prospectively enrolled 100 patients with CRC confirmed by histo-pathology.All patients received preoperative CEUS examinations.Quantitative parameters,such as peak intensity(PI),time to peak(TTP),and area under the curve(AUC),were derived from time-intensity curve(TIC)analysis.Tumour tissue samples were obtained during surgery and examined immunohistochem-ically to assess the expression of angiogenesis markers,including vascular endo-thelial growth factor(VEGF)and microvessel density(MVD).The correlation between CEUS parameters,angiogenesis markers,and clinicopathological features was evaluated using appropriate statistical tests.RESULTS Quantitative CEUS parameters(PI,TTP,and AUC)showed significant correlations with VEGF expression(P<0.001)and MVD(P<0.001),indicating a strong link between tumour blood vessels and angiogenesis.Increased PI,reduced TTP,and expanded AUC values were significantly related to higher tumour stage(P<0.001),lymph node metastasis(P<0.001),and distant metastasis(P<0.001).Furthermore,these parameters were recognized as independent predictors of overall survival and disease-free survival in multivariate analysis(P<0.001).CONCLUSION CEUS has a high potential in guiding treatment planning and predicting patient outcomes.However,more com-prehensive,multicentre studies are required to validate the clinical utility of CEUS in CRC management.展开更多
The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), 1 (Yellow inhibitor) and C ( Outer-layer yellow cocoon), which are located on linkage groups 2, 9 a...The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), 1 (Yellow inhibitor) and C ( Outer-layer yellow cocoon), which are located on linkage groups 2, 9 and 12, respectively. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progeny were used for linkage analysis and mapping of the C gene using silkworm strains C 108 and KY, which spin white and yellow cocoons, respectively. DNA was extracted from individual pupae and analyzed for simple sequence repeat (SSR) markers. The C gene was found to be linked to seven SSR markers. All the yellow cocoon individuals from a female heterozygous backcross (BC1F) showed a heterozygous profile for SSR markers on linkage group 12, whereas individuals with light yellow cocoons showed the homozygous profile of the strain C108. Using a reciprocal heterozygous male backcross (BC1M), we constructed a linkage map of 36.4 cM with the C gene located at the distal end, and the closest SSR marker at a distance of 13.9 cM.展开更多
Background: Estimating the grades of liver inflammation is critical in the determination ofantiviral therapy in patients chronically infected with hepatitis B virus (HBV). The aim of this study was to investigate t...Background: Estimating the grades of liver inflammation is critical in the determination ofantiviral therapy in patients chronically infected with hepatitis B virus (HBV). The aim of this study was to investigate the correlation ofserum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) with the liver inflammation grades in treatment-naTve patients with chronic HBV infection. Methods: We retrospectively enrolled 584 treatment-na'l've HBeAg-positive patients who underwent liver biopsy in Ditan Hospital from January 2008 to January 2016. Based on the severity of liver inflammation, the patients were divided into minimal, mild, and moderate groups. SPSS software was used lbr statistical analysis of all relevant data. Results: The liver histological examinations showed that 324, 194, and 66 patients had minimal, mild, and moderate liver inflammation, respectively. The median age of the three groups was 30, 33, and 38 years, respectively (X2 =26.00, P 〈 0.001 ). The median HBsAg levels in minimal, mild, and moderate inflammation groups were 4.40, 4.16, and 3.67 log U/ml, respectively, and the median HBeAg levels in the three groups were 3.12, 2.99, and 1.86 log sample/cutoff. respectively; both antigens tended to decrease as the grade of inflammation increased (X2 = 99.68 and X2 =99.23, respectively; both P 〈 0.001 ). The cutoff values of receiver operating characteristic curve in the age, HBsAg and HBeAg levels were 36 years, 4.31 log U/ml, and 2.86 Iog S/CO, respectively, 1 to distinguish minimal grade and other grades of treatment-naTve HBeAg-positive patients with chronic HBV infection. Conclusions: Serum HBsAg and HBeAg quantitation might gradually decrease with aggravated liver inflammation and the corresponding cutoff values rnight help us to distinguish rninimal grades and other grades and detect those who do not need antiviral therapy in treatment-naive HBeAg-positive patients with chronic HBV infection.展开更多
Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability challenges.Transition metal dichalcogenide(TMD)-based ...Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability challenges.Transition metal dichalcogenide(TMD)-based single-atom catalysts are considered highly effective in electrocatalysis due to the TMDs'notable specific surface area,tunable elemental species and efficient utilization of single atoms.In order to enhance electrocatalytic performance,it is imperative to elaborately engineer the local environment surrounding the active sites of single atoms within TMDs.In this review,we initially explore the effects of synthesis methods on single-atom active sites and the influence of loading of single atoms on catalytic performance for TMDs.The modulation strategies of the local environment surrounding single-atom sites in TMDs are elaborated,including substitution engineering,surface adsorption,vacancies,spatial confinement and dual-atom site strategies.For each modulation strategy,the effects of diverse local environments on various electrocatalytic applications are presented,such as the oxygen evolution reaction,oxygen reduction reaction,nitrogen reduction reaction,CO_(2)reduction reaction and CO oxidation.Ultimately,this study presents a comprehensive overview of the challenges encountered and the potential directions for the advancement of single-atom catalysts based on TMDs in the realm of electrocatalysis.展开更多
文摘BACKGROUND Pituitary stalk interruption syndrome(PSIS)is a rare disorder,often characterized by delayed growth and development,short stature,and hypogonadism as the main clinical manifestations.It is not clear whether PSIS can lead to liver cirrhosis.CASE SUMMARY This paper reported a case of liver cirrhosis of unknown origin.The patient was admitted to Beijing Ditan Hospital Affiliated to Capital Medical University in November 2023.The diagnosis of PSIS complicated with liver cirrhosis was established after a series of blood tests and pituitary magnetic resonance imaging examination.CONCLUSION We also reviewed the literature from both domestic and international sources to deepen the clinical understanding of PSIS in conjunction with liver cirrhosis among medical practitioners.
基金the National Natural Science Foundation of China(No.11475261)partially supported by the National Key Project of Research and Development of China(No.2016YFC0904600).
文摘The aim of this study was to design a cage-like radiotherapy system(CRTS)to further promote the clinical application of noncoplanar radiotherapy.The CRTS comprises two stands,two O-rings,several arc girders,an X-ray head,an imaging subsystem,and a treatment couch.The X-ray head rotates with O-rings around the patient’s body and slides along the arc girder.Compared with the C-arm linear accelerator(C-Linac),the clinically available spatial irradiation angle ranges(SIARs)of the CRTS for the head,chest,and abdomen were 33%,63.6%,and 62.6%larger,respectively.Moreover,according to a preliminary planning comparison based on the dose distribution simulation method,the CRTS achieved much better protection of normal tissue than the C-Linac.Furthermore,the CRTS enabled accurate noncoplanar irradiation without movement of the body being irradiated,allowed automatic control of the movements of different parts without risk of collisions,and provided continuous radiation over an angle that considerably exceeded a full turn.These advantages make CRTS very promising for noncoplanar radiotherapy.
文摘To investigate the effects of individualised treatment with peginterferon alpha-2a(40 kD)plus ribavirin in Chinese patients with CHC.Methods Total of 297 consecutive Chinese patients were enrolled,including 250 nave cases and 47 cases who were previously treated.Treatment duration was determined according to viral genotypes,prior treatment history and viral responses at week 4,12 and 24.Results Totally,235 patients(79.1%)completed treatment and 186(87.3%)achieved SVR.And 219 out of 289(75.8%)patients achieved HCV RNA negative at week 4(RVR)and 259 of 276(93.8%)at week 12.Among the 164 patients with RVR who completed follow-up,158(96.3%)achieved SVR.Patients with RVR had lower baseline viral loads than patients without RVR(P=0.034).The positive predictive value(PPV)of RVR for SVR was 90.7%(OR 2.10 vs.non-RVR,95%CI:0.50-8.7).Similar outcomes were observed among patients with HCV undetectable at week 12.Conclusions Viral suppression by week 4 is associated with a high rate of treatment success in treatment nave and experienced patients receiving individualized CHC therapy.
基金supported by Scientific Research Projects of Beijing Ditan HospitalCapital Medical University+1 种基金Projects from Beijing Municipal Science and Technology Commission (D171100003117005)Digestive Medical Coordinated Development Center of Beijing Hospitals Authority (XXZ0402)。
文摘Background: Recent studies reported that patients with coronavirus disease-2019(COVID-19) might have liver injury. However, few data on the combined analysis and change patterns of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and total bilirubin(TBil) have been shown.Methods: This is a single-center retrospective study. A total of 105 adult patients hospitalized for confirmed COVID-19 in Beijing Ditan Hospital between January 12, and March 17, 2020 were included, and divided into mild group(n=79) and severe group(n=26). We compared liver functional test results between the two groups. Category of ALT change during the disease course was also examined.Results: 56.2%(59/105) of the patients had unnormal ALT, AST, or total TBil throughout the course of the disease, but in 91.4%(96/105) cases the level of ALT, AST or TBil ≤3 fold of the upper limit of normal reference range(ULN). The overall distribution of ALT, AST, and TBil were all significantly difference between mild and severe group(P<0.05). The percentage of the patients with elevated both ALT and AST was 12.7%(10/79) in mild cases vs. 46.2%(12/26) in severe cases(P=0.001). 34.6%(9/26) severe group patients started to have abnormal ALT after admission, and 73.3%(77/105) of all patients had normal ALT before discharge.Conclusions: Elevated liver function index is very common in patients with COVID-19 infection, and the level were less than 3×ULN, but most are reversible. The abnormality of 2 or more indexes is low in the patients with COVID-19, but it is more likely to occur in the severe group.
基金Supported by 2024 Zhejiang Province Traditional Chinese Medicine Science and Technology Plan,No.2024ZL1129,No.2024ZL1130.
文摘BACKGROUND This case series investigated the clinical manifestations,diagnoses,and treatment of cerebral abscesses caused by Streptococcus anginosus.We retrospectively analyzed the clinical characteristics and outcomes of three cases of cerebral abscesses caused by Streptococcus anginosus and conducted a comprehensive review of relevant literature.CASE SUMMARY Case 1 presented with a history of left otitis media and exhibited high fever,confusion,and vomiting as primary symptoms.Postoperative pus culture indicated a brain abscess caused by Streptococcus constellatus infection.Case 2 experienced dizziness for two days as the primary symptom.Postoperative pus culture suggested an intermediate streptococcal brain abscess.Case 3:Enhanced head magnetic resonance imaging(MRI)and diffusion-weighted imaging revealed occupancy of the left temporal lobe,initially suspected to be a metastatic tumor.However,a postoperative pus culture confirmed the presence of a brain abscess caused by Streptococcus anginosus infection.The three cases presented in this case series were all patients with community-acquired brain abscesses resulting from angina caused by Streptococcus group infection.All three patients demonstrated sensitivity to penicillin,ceftriaxone,vancomycin,linezolid,chloramphenicol,and levofloxacin.Successful treatment was achieved through stereotaxic puncture,drainage,and ceftriaxone administration with a six-week course of antibiotics.CONCLUSION Preoperative enhanced head MRI plays a critical role in distinguishing brain tumors from abscesses.Selecting the correct early diagnostic methods for brain abscesses and providing timely intervention are very important.This case series was in accordance with the CARE guidelines.
基金Supported by The National Key Research and Development Program,No.2022YFC2603500 and No.2022YFC2603505Beijing Municipal Health Commission High-Level Public Health Technical Personnel Construction Project,No.Discipline leader-03-26+2 种基金The Digestive Medical Coordinated Development Center of Beijing Hospitals Authority,No.XXZ0302The Capital Health Research and Development of Special Public Health Project,No.2022-1-2172and Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support,No.XMLX 202127.
文摘Hepatitis B virus(HBV)infection plays an important role in the occurrence and development of hepatocellular carcinoma(HCC),and the rate of HBV infection in liver cancer patients in China is as high as 92.05%.Due to long-term exposure to chronic antigens from the gut,the liver needs to maintain a certain level of immune tolerance,both to avoid severe inflammation caused by non-pathogenic antigens and to maintain the possibility of rapid and violent responses to infection and tumors.Therefore,HBV infection interacts with the tumor microenvironment(TME)through a highly complex and intertwined signaling pathway,which results in a special TME in HCC.Due to changes in the TME,tumor cells can evade immune surveillance by inhibiting tumor-specific T cell function through cytotoxic T-lymphocy-associated protein-4(CTLA-4)and programmed cell death 1(PD-1)/programmed cell death ligand 1(PD-L1).Interferons,as a class of immune factors with strong biological activity,can improve the TME of HBV-HCC through various pathways.In recent years,the systematic treatment of HCC has gradually come out of the dilemma.In addition to the continuous emergence of new multi-target anti-vascular tyrosine kinase inhibitor drugs,immune checkpoint inhibitors have opened up a new avenue for the systematic treatment of HCC.At present,immunotherapy based on PD-1/L1 inhibitors has gradually become a new direction of systematic treatment for HCC,and the disease charac-teristics of patients included in global clinical studies are different from those of Chinese patients.Therefore,whether a group of HCC patients with HBV background and poor prognosis in China can also benefit from immunotherapy is an issue of wide concern.This review aims to elucidate the advances of immuno-therapy for HBV related HCC patients with regard to:(1)Immunotherapy based on interferons;(2)Immunotherapy based on PD-1/L1 inhibitors;(3)Immunotherapy based on CTLA4 inhibitors;(4)Adoptive cell transfer;(5)Combination immunotherapy strategy;and(6)Shortcomings of immunotherapy.
文摘AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, who were treatment-naive, with a serum HBs Ag level < 100 IU/m L and an undetectable hepatitis B virus(HBV) DNA level(< 100 IU/m L). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBs Ag, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen(65.0%) of 20 treated patients achieved HBs Ag loss, 12 of whom achieved HBs Ag seroconversion. Mean HBs Ag level in treated patients decreased to 6.69 ± 13.04 IU/m L after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/m L. Serum HBV DNA level remained undetectable(< 100 IU/m L) in all treated patients during the study. HBs Ag level of the control group decreased from 25.72 ± 25.58 IU/m L at baseline to 17.11 ± 21.62 IU/m L at week 96(P = 0.108). In the control group, no patient experienced HBs Ag loss/seroconversion, and two(5.0%) developed HBV reactivation.CONCLUSION: IFN treatment results in HBs Ag loss and seroconversion in a considerable proportion of inactive HBs Ag carriers with low HBs Ag concentrations.
文摘BACKGROUND: The availability of novel direct-acting antivirals (DAAs) represents a new era of curative hepatitis C virus (HCV) treatment, with over 95% of patients infected with HCV genotype 1 achieving sustained virological response (SVR). Nevertheless, the majority of patients globally are unable to access these treatments because of cost and infrastructure constraints and, thus, remain untreated and uncured. DATA SOURCE: Relevant articles of peginterferon (PegIFN)-based treatments in HCV and sofosbuvir-based treatments, simeprevir, daclatasvir/asunaprevir, ritonavir-boosted paritaprevir/ombitasvir/dasabuvir, and grazoprevir/elbasvir, were searched in PubMed database, including general population and special population. RESULTS: PegIFN in combination with ribavirin remains an important and relevant option for some patients, achieving SVR rates of up to 79% in genotype 1 and 89% in genotype 2 or 3 infections, which increases for patients with favorable IL28B genotypes. Triple therapy of DAA plus PegIFN/ribavirin is effective in treating difficult-to-cure patients infected with HCV genotype 3 or with resistance-associated variants. Owing to its long history in HCV management, the efficacy, tolerability and long-term outcomes associated with PegIFN alfa-2a are well established and have been validated in large-scale studies and in clinical practice for many populations. Furthermore, emerging data show that IFN-induced SVR is associated with lower incidences of hepatocellular carcinoma compared with DAAs. On the contrary, novel DAAs have yet to be studied in special populations, and long-term outcomes, particularly tumor development and recurrence in patients with cirrhosis and/or hepatocellular carcinoma, and reactivation of HBV in dually infected patients, are still unclear. CONCLUSION: In this interferon-free era, PegIFN-based regimens remain a safe and effective option for selected HCV patients.
基金the National Natural Science Foundation of China fund (Project number: 52174045 and No. 52104011)Research Foundation of China University of Petroleum-Beijing at Karamay (No. XQZX20210001)PetroChina Innovation Foundation (2020D50070207)。
文摘Due to the reservoir heterogeneity and the stress shadow effect, multiple hydraulic fractures within one fracturing segment cannot be initiated simultaneously and propagate evenly, which will cause a low effectiveness of reservoir stimulation. Temporary plugging and diverting fracturing(TPDF) is considered to be a potential uniform-stimulation method for creating multiple fractures simultaneously in the oilfield. However, the multi-fracture propagation morphology during TPDF is not clear now. The purpose of this study is to quantitatively investigate the multi-fracture propagation morphology during TPDF through true tri-axial fracturing experiments and CT scanning. Critical parameters such as fracture spacing, number of perforation clusters, the viscosity of fracturing fluid, and the in-situ stress have been investigated. The fracture geometry before and after diversion have been quantitively analyzed based on the two-dimensional CT slices and three-dimensional reconstruction method. The main conclusions are as follows:(1) When injecting the high viscosity fluid or perforating at the location with low in-situ stress, multiple hydraulic fractures would simultaneously propagate. Otherwise, only one hydraulic fracture was created during the initial fracturing stage(IFS) for most tests.(2) The perforation cluster effectiveness(PCE) has increased from 26.62% during the IFS to 88.86% after using diverters.(3) The diverted fracture volume has no apparent correlation with the pressure peak and peak frequency during the diversion fracturing stage(DFS) but is positively correlated with water-work.(4) Four types of plugging behavior in shale could be controlled by adjusting the diverter recipe and diverter injection time, and the plugging behavior includes plugging the natural fracture in the wellbore, plugging the previous hydraulic fractures, plugging the fracture tip and plugging the bedding.
基金financially supported by the National Natural Science Foundation of China(No.52174045,No.52104011)Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01B77)。
文摘Intra-stage multi-cluster temporary plugging and diverting fracturing(ITPF)is one of the fastest-growing techniques to obtain uniform reservoir stimulation in shale gas reservoirs.However,propagation geometries of multiple fractures during ITPF are not clear due that the existing numerical models cannot capture the effects of perforation plugging.In this paper,a new three-dimensional FEM based on CZM was developed to investigate multiple planar fracture propagation considering perforation plugging during ITPF.Meanwhile,the fluid pipe element and its subroutine were first developed to realize the flux partitioning before or after perforation plugging.The results showed that the perforation plugging changed the original distribution of the number of perforations in each fracture,thus changing the flux partitioning after perforation plugging,which could eliminate the effect of stress interference between multiple fractures and promote a uniform fluid distribution.The standard deviation of fluid distribution in the perforation plugging case was only 8.48%of that in the non-diversion case.Furthermore,critical plugging parameters have been investigated quantitatively.Specifically,injecting more diverters will create a higher fluid pressure rise in the wellbore,which will increase the risk of wellbore integrity.Comprehensively considering pressure rise and fluid distribution,the number of diverters should be 50%of the total number of perforations(N_(pt)),whose standard deviation of fluid distribution of multiple fractures was lower than those in the cases of injecting 10%N_(pt),30%N_(pt)and 70%N_(pt).The diverters should be injected at an appropriate timing,i.e.40%or 50%of the total fracturing time(tft),whose standard deviation of the fluid distribution was only about 20%of standard deviations in the cases of injecting at20%tftor 70%tft.A single injection with all diverters can maintain high bottom-hole pressure for a longer period and promote a more uniform fluid distribution.The standard deviation of the fluid distribution in the case of a single injection was 43.62%-55.41%of the other cases with multiple injection times.This study provides a meaningful perspective and some optimal plugging parameters on the field design during IPTF.
基金supported by the Major New Drug Creation Program from National Science and Technology Major Project of China(2014ZX09303305).
文摘Background Uncertainty remains regarding the association between body mass index(BMI)and the risk of bleeding in patients with non-valvular atrial fibrillation(NVAF).We aimed to investigate the association between BMI and the risk of bleeding in elderly NVAF patients taking dabigatran.Methods A total of 509 elderly NVAF patients,who were being treated at twelve centers in China from February 2015 to December 2017 and taking dabigatran,were analyzed.The exposure and outcome variables were BMI at baseline and bleeding events within the subsequent six months,respectively.Cox proportional hazards regression analysis was used to evaluate the association between BMI and the risk of bleeding.Moreover,the Cox proportional hazards regression with cubic spline functions and smooth curve fitting was conducted.Results During the six-month follow-up,50 participants experienced bleeding.Every 1 kg/m^2 increase in BMI was associated with a 12%increased risk of bleeding(P=0.021).Compared to those with BMI values in Tertile 1(<22.5 kg/m^2),the adjusted hazard ratio(HR)of bleeding for participants in Tertile 2(22.5–25.3 kg/m^2)and Tertile 3(>25.3 kg/m^2)were 2.71(95%CI:1.02–7.17)and 3.5(95%CI:1.21–8.70),respectively.The Ptrend-value was significant in all models.The adjusted smooth curve showed a linear association between BMI and bleeding.None of the stratified variables showed significant effect modification on the association between BMI and bleeding(Pinteraction>0.05).Conclusions BMI was significantly and positively associated with the risk of bleeding in elderly NVAF patients treated with dabigatran.
基金The project was supported by the Grants (2003BA712A08-02 and 2004BA718B03) from the Chinese Ministry of Science and Technology.
文摘Saliva and blood were collected from two patients who had not received post exposure prophylaxis in the cities of Wenzhou and Xinning respectively. Both patients were confirmed as positive for rabies by detection of rabies virus specific nucleoprotein antibodies in the sera by Western Blot. However, rabies virus specific RNA was only identified in the saliva collected from the patient in Wenzhou. Furthermore, the isolate Zhejiang Wz0 (H) was obtained by inoculating one-day-old suckling mice. Both nucleoprotein (N) and glycoprotein (G) genes from the isolate were amplified by RT-PCR and sequenced. Phylogenetic analysis indicated that the isolate belonged to classic rabies virus, and shared a higher homology with the street viruses from dogs in the main endemic areas in China and the street virus from dogs in Indonesia than with other known strains. Further comparison of the deduced amino acid sequences between the isolate and the vaccine strains used in China showed that the virus had a higher level of homology with the vaccine strain CTN than with the other vaccine strains (3aG, PV, PM and ERA). In particular, amino acid residues substitutions located in antigenic site Ⅲ in the G protein, which could react with the neutralizing antibodies, were observed. These results suggested that the virus belonged to the classic rabies virus, and both N and G genes diverged from the current vaccine strains used in China at either the nucleotide or the amino acid level.
基金support from the China University of Petroleum(Beijing)School for Young Talent Startup Fund(No.ZX20190183).
文摘Fracture propagation is affected by multi-metal-veins formed by geological diagenesis in shale during the hydraulic fracturing.However,the influence of multi-metal-veins on fractures propagation remains unclear.To solve the problem,based on the semi-circle bending(SCB)test and the extended finite element(XFEM)theory,the interaction between multi-metal-veins and fractures is investigated.The experimental results reveal that the fractures usually deflect at the upper or lower interfaces between metal veins and rocks(e.g.the specimen S-2),which is different from the propagation behavior of fractures in calcite veins.Meanwhile,the fracture toughness of the specimen S-1 is 24.40%higher than that of the specimen S-2,indicating that the increasing of total thickness of multiple metal veins in-creases the resistance to the fracture vertical propagation.The simulation results show that the increasing of the number,total thickness of veins,the modulus difference between veins and rock,the approach angle and the notch angle all increase the resistance of the fracture passing through metal veins.The maximum deviation distance(Dmax)of the fracture decreases with the number of veins,while thickness combination types of metal veins do not affect Dmax.The reduction of the notch angle leads to the more tortuous fracture propagation path.Finally,we propose a new comprehensive fracture network pattern.Fracture networks are divided into two categories,including orthogonal fracture networks and sub-orthogonal fracture networks,and then divided into six sub-categories further.The research results will provide reference for hydraulic fracturing of shale reservoirs containing multi-metal-veins.
基金supported by the National SKA Program of China No.2020SKA0120100the National Natural Science Foundation of China(NSFC,Grant Nos.11963002,11703047,11773041,U2031119,12173052,12003047 and 12173053)+7 种基金the fostering project of Guizhou University with No.201911Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CASsupported by the Specialized Research Fund for State Key Laboratoriessupported by the CAS“Light of West China”Programthe Youth Innovation Promotion Association of CAS(id 2023064)supported by the Youth Innovation Promotion Association of CAS(id.2018075 and Y2022027)supported by Guizhou Provincial Basic Research Program(Natural Science)(ZK[2023]039)Key Technology R&D Program([2023]352)。
文摘Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation between average dispersion measure(■)and dispersion measure difference(ΔDM)of known pulsars in GCs is lgΔDM∝1.52lg■.The sensitivity could be the key to finding more pulsars.As a result,several years after the construction of a large radio telescope facility,the number of known GC pulsars will likely be increased accordingly.We suggest that currently GCs in the southern hemisphere could have higher possibilities for finding new pulsars.
基金the National Natural Science Foundation of China(Grant No.11673039)the Open Project Program of the Key Laboratory of FAST,NAOC,Chinese Academy of Sciencesthe Key Laboratory of Radio Astronomy,Chinese Academy of Sciences。
文摘This paper presents a new measurement system based on integration method that can provide all-weather dependability and higher precision for the measurement of FAST's feed support system.The measurement system consists of three types of measuring equipments,and a processing software with the core data fusion algorithm.The Strapdown Inertial Navigation System(SINS)can autonomously measure the position,speed and attitude of the carrier.Its own shortcoming is that the measurement data diverge rapidly over time.SINS must combine the Global Positioning System(GPS)and the Total Station(TS)to obtain high-precision measurement data.The Kalman filtering algorithm is adopted for the integration measurement system,which is an optimal algorithm to estimate the measurement errors.A series of tests are carried out to evaluate the performance.For the feed cabin,the maximum RMS of the position is 14.56 mm,the maximum RMS of the attitude is 0.095,these values are less than 15 mm and 0.1°as the precision for measuring the feed cabin.For the Stewart manipulator,the maximum RMS of the position is 2.99 mm,the maximum RMS of the attitude is 0.093°,these values are less than 3 mm and 0.1°as the precision for measuring the Stewart manipulator.As a result,the new measurement meets the requirement of measurement precision for FAST's feed support system.
文摘BACKGROUND Ultrasound is a vital tool for the diagnosis and management of colorectal cancer(CRC).Contrast-enhanced ultrasound(CEUS)is a non-invasive,safe,and cost-effective method for evaluating tumour blood vessels,that play a crucial role in tumour growth and progression.AIM To explore CEUS’s role in the quantitative evaluation of CRC blood vessels and their correlation with angiogenesis markers and prognosis.METHODS This study prospectively enrolled 100 patients with CRC confirmed by histo-pathology.All patients received preoperative CEUS examinations.Quantitative parameters,such as peak intensity(PI),time to peak(TTP),and area under the curve(AUC),were derived from time-intensity curve(TIC)analysis.Tumour tissue samples were obtained during surgery and examined immunohistochem-ically to assess the expression of angiogenesis markers,including vascular endo-thelial growth factor(VEGF)and microvessel density(MVD).The correlation between CEUS parameters,angiogenesis markers,and clinicopathological features was evaluated using appropriate statistical tests.RESULTS Quantitative CEUS parameters(PI,TTP,and AUC)showed significant correlations with VEGF expression(P<0.001)and MVD(P<0.001),indicating a strong link between tumour blood vessels and angiogenesis.Increased PI,reduced TTP,and expanded AUC values were significantly related to higher tumour stage(P<0.001),lymph node metastasis(P<0.001),and distant metastasis(P<0.001).Furthermore,these parameters were recognized as independent predictors of overall survival and disease-free survival in multivariate analysis(P<0.001).CONCLUSION CEUS has a high potential in guiding treatment planning and predicting patient outcomes.However,more com-prehensive,multicentre studies are required to validate the clinical utility of CEUS in CRC management.
基金Acknowledgments This project was supported by the National Basic Research (973) Program (grant no. 2005CB121000), Natural Science Foundation of Jiangsu Province (grant no. BK2006508), Hi-tech Research and Development Program (863) of China (2006AA10A119).
文摘The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), 1 (Yellow inhibitor) and C ( Outer-layer yellow cocoon), which are located on linkage groups 2, 9 and 12, respectively. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progeny were used for linkage analysis and mapping of the C gene using silkworm strains C 108 and KY, which spin white and yellow cocoons, respectively. DNA was extracted from individual pupae and analyzed for simple sequence repeat (SSR) markers. The C gene was found to be linked to seven SSR markers. All the yellow cocoon individuals from a female heterozygous backcross (BC1F) showed a heterozygous profile for SSR markers on linkage group 12, whereas individuals with light yellow cocoons showed the homozygous profile of the strain C108. Using a reciprocal heterozygous male backcross (BC1M), we constructed a linkage map of 36.4 cM with the C gene located at the distal end, and the closest SSR marker at a distance of 13.9 cM.
文摘Background: Estimating the grades of liver inflammation is critical in the determination ofantiviral therapy in patients chronically infected with hepatitis B virus (HBV). The aim of this study was to investigate the correlation ofserum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) with the liver inflammation grades in treatment-naTve patients with chronic HBV infection. Methods: We retrospectively enrolled 584 treatment-na'l've HBeAg-positive patients who underwent liver biopsy in Ditan Hospital from January 2008 to January 2016. Based on the severity of liver inflammation, the patients were divided into minimal, mild, and moderate groups. SPSS software was used lbr statistical analysis of all relevant data. Results: The liver histological examinations showed that 324, 194, and 66 patients had minimal, mild, and moderate liver inflammation, respectively. The median age of the three groups was 30, 33, and 38 years, respectively (X2 =26.00, P 〈 0.001 ). The median HBsAg levels in minimal, mild, and moderate inflammation groups were 4.40, 4.16, and 3.67 log U/ml, respectively, and the median HBeAg levels in the three groups were 3.12, 2.99, and 1.86 log sample/cutoff. respectively; both antigens tended to decrease as the grade of inflammation increased (X2 = 99.68 and X2 =99.23, respectively; both P 〈 0.001 ). The cutoff values of receiver operating characteristic curve in the age, HBsAg and HBeAg levels were 36 years, 4.31 log U/ml, and 2.86 Iog S/CO, respectively, 1 to distinguish minimal grade and other grades of treatment-naTve HBeAg-positive patients with chronic HBV infection. Conclusions: Serum HBsAg and HBeAg quantitation might gradually decrease with aggravated liver inflammation and the corresponding cutoff values rnight help us to distinguish rninimal grades and other grades and detect those who do not need antiviral therapy in treatment-naive HBeAg-positive patients with chronic HBV infection.
基金supported by the“Teli Young Scholar”ProgramTechnology Innovation Program of Beijing Institute of Technology+2 种基金“Xiaomi Scholar”Program“Langyue”ProgramBeijing Municipal Natural Science Foundation(No.2232023)。
文摘Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability challenges.Transition metal dichalcogenide(TMD)-based single-atom catalysts are considered highly effective in electrocatalysis due to the TMDs'notable specific surface area,tunable elemental species and efficient utilization of single atoms.In order to enhance electrocatalytic performance,it is imperative to elaborately engineer the local environment surrounding the active sites of single atoms within TMDs.In this review,we initially explore the effects of synthesis methods on single-atom active sites and the influence of loading of single atoms on catalytic performance for TMDs.The modulation strategies of the local environment surrounding single-atom sites in TMDs are elaborated,including substitution engineering,surface adsorption,vacancies,spatial confinement and dual-atom site strategies.For each modulation strategy,the effects of diverse local environments on various electrocatalytic applications are presented,such as the oxygen evolution reaction,oxygen reduction reaction,nitrogen reduction reaction,CO_(2)reduction reaction and CO oxidation.Ultimately,this study presents a comprehensive overview of the challenges encountered and the potential directions for the advancement of single-atom catalysts based on TMDs in the realm of electrocatalysis.