BACKGROUND Magnetic resonance imaging(MRI)scanning with susceptibility weighted imaging(SWI)sequences plays a significant role in the diagnosis and prognostic evaluation of neonatal hypoxic-ischemic encephalopathy(HIE...BACKGROUND Magnetic resonance imaging(MRI)scanning with susceptibility weighted imaging(SWI)sequences plays a significant role in the diagnosis and prognostic evaluation of neonatal hypoxic-ischemic encephalopathy(HIE).AIM To observe the role of MRI multi-parameter quantitative indexes in the diagnosis of neonatal HIE.METHODS The imaging data from 23 cases of neonatal HIE admitted to the Imaging Department of Ganyu District People's Hospital of Lianyungang City and 23 neonates without HIE admitted during the same period were analyzed retrospectively from August,2021 to December,2023.The results of clinical judgment were compared with the results of computed tomography(CT)and MRI examinations.RESULTS The degree of cerebral edema(more than moderate),the number of damaged brain regions(>2),the number of cerebral hemorrhages(>2),and the percentage of small venous dilatation detected were higher in MRI than in CT examination,and the differences were statistically significant(P<0.05).The total area of the largest region of cerebral damage and of cerebral hemorrhage observed by MRI examination were significantly larger than those of CT examination(P<0.01).Multiparametric quantitative MRI combined with diffusion weighted imaging and SWI had higher sensitivity and accuracy than CT diagnosis,and the difference was statistically significant(P<0.05).The difference in the specificity of the two modes of diagnosis was not significant(P>0.05).CONCLUSION The use of MRI multi-parameter quantitative indexes can accurately diagnose and evaluate neonatal HIE.展开更多
Accurate prediction of the rate of penetration(ROP)is significant for drilling optimization.While the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations...Accurate prediction of the rate of penetration(ROP)is significant for drilling optimization.While the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its credibility.This study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified Linear Unit(ReLU)activation function.By leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector operations.The FNN model is linearly characterized through further simplification,enabling its interpretation and analysis.The proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim Oilfield.The results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally well.The relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data similarity.In the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation equation.Furthermore,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well section.The established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.展开更多
A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide fuel.FH-NCM/S1 adopt...A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide fuel.FH-NCM/S1 adopts an inte-grated approach,combining the shift register analysis mode with the pulse-position timestamp mode using an FPGA.The optimal effective length of the^(3)He neutron detector was determined to be 30 cm,and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP simulations.After fabricating the device,calibration measurements were per-formed using a^(252)Cf neutron source;a detection efficiency of 43.07%and detector die-away time of 55.79μs were observed.Nine samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity counter.The obtained double rates underwent corrections for detection efficiency(ε)and double gate fraction(f_(d)),resulting in corrected double rates(D_(c)),which were used to validate the accuracy of the shift register analysis mode.Furthermore,the device exhibited fluctuations in the measurement results,and within a single 20 s measurement,these fluctuations remained below 10%.After 30 cycles,the relative error in the mass of^(240)Pu was less than 5%.Finally,correlation calculations confirmed the robust consistency of both measurement modes.This study holds specific significance for the subsequent design and development of neutron multiplicity devices.展开更多
The reference-frame-independent(RFI)quantum key distribution(QKD)is suitable for satellite-based links by removing the active alignment on the reference frames.However,how the beam wandering influences the performance...The reference-frame-independent(RFI)quantum key distribution(QKD)is suitable for satellite-based links by removing the active alignment on the reference frames.However,how the beam wandering influences the performance of RFI-QKD remains a pending issue in satellite-to-ground links.In this paper,based on the mathematical model for characterizing beam wandering,we present the security analysis for satellite-to-ground RFI-QKD and analytically derive formulas for calculating the secret key rate with beam wandering.Our simulation results show that the performance of RFI-QKD is better than the Bennett–Brassard 1984(BB84)QKD with beam wandering in asymptotic case.Furthermore,the degree of influences of beam wandering is specifically presented for satellite-to-ground RFI-QKD when statistical fluctuations are taken into account.Our work can provide theoretical support for the realization of RFI-QKD using satellite-to-ground links and have implications for the construction of large-scale satellite-based quantum networks.展开更多
The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In...The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest.展开更多
AgSnO_ 2 electrical contact materials doped with Bi_2O_3,La_2O_3,and TiO_2 were successfully fabricated by the powder metallurgy method under different initial sintering temperatures.The electrical conductivity,densit...AgSnO_ 2 electrical contact materials doped with Bi_2O_3,La_2O_3,and TiO_2 were successfully fabricated by the powder metallurgy method under different initial sintering temperatures.The electrical conductivity,density,hardness,and contact resistance of the Ag Sn O_2/Bi_2O_3,AgSnO_2/La_2O_3,and AgSnO_2/Ti O_2 contact materials were measured and analyzed.The arc-eroded surface morphologies of the doped AgSnO_2 contact materials were investigated by scanning electron microscopy(SEM).The effects of the initial sintering temperature on the physical properties and electrical contact properties of the doped AgSnO_2 contact materials were discussed.The results indicate that the physical properties can be improved and the contact resistance of the AgSnO_2 contact materials can be substantially reduced when the materials are sintered under their optimal initial sintering temperatures.展开更多
A suite of ultramafic and mafic rocks developed in the Chigu Tso area,eastern Tethyan Himalaya.Baddeleyite and zircon U-Pb ages acquired by SIMS and LA-ICP-MS from olivine pyroxenite rocks in the Chigu Tso area are 13...A suite of ultramafic and mafic rocks developed in the Chigu Tso area,eastern Tethyan Himalaya.Baddeleyite and zircon U-Pb ages acquired by SIMS and LA-ICP-MS from olivine pyroxenite rocks in the Chigu Tso area are 138.9±3.0 Ma and 139.0±1.9 Ma,respectively.These two Early Cretaceous ages are similar with the ages of the more abundant mafic rocks in the eastern Tethyan Himalaya,indicating that this suite of ultramafic and mafic rocks in the Chigu Tso area should be included in the outcrop area of the Comei Large Igneous Province(LIP).These ultramafic rocks provide significant evidence that the involvement of mantle plume/hot spot activities in the formation of the Comei LIP.Baddeleyite U-Pb dating by SIMS is one reliable and convenient method to constrain the formation time of ultramafic rocks.The dating results of baddeleyite and zircon from the olivine pyroxenite samples in this paper are consistent with each other within analytical uncertainties,suggesting that baddeleyite and zircon were both formed during the same magmatic process.The consistency of baddeleyite U-Pb ages in the Chigu Tso area with zircon U-Pb ages for a large number of Early Cretaceous mafic rocks in the eastern Tethyan Himalaya further support that zircon grains from such mafic rocks yielding Early Cretaceous ages are also magmatic in origin.展开更多
The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reac...The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reactor and steam generator modules with a thermal power of 250 MW_(th)and power generation of approximately 100 MW_(e)per module.Six modules in parallel,connected to a steam turbine,form a 600-MW_(e)nuclear power plant.In addition,its system configuration in the nuclear island is identical to that of the HTR-PM in which the technical risks are minimized.Under this principle,the HTR-PM600 achieves the same level of inherent safety as the HTR-PM.The concept of a ventilated lowpressure containment(VLPC)is unchanged;however,a large circular VLPC accommodating all six reactor modules is adopted rather than the previous small-cavity-type VLPC,which contains only one module,as defined for the HTR-PM.The layout of the nuclear island and its associated systems refer to single-unit pressurized water reactor(PWR)practices.With this layout,the HTR-PM600achieves a volume size of the nuclear island that is comparable to a domestic PWR of the same power level.This will be a GenerationⅣnuclear energy technology that is economically competitive.展开更多
Objective To explore the change of endogenic nerve growth factor (NGF) expression in human glioma cells infected with human cytomegalovirus (HCMV). Methods U251 cells were cultured in RPMI 1640 culture medium and ...Objective To explore the change of endogenic nerve growth factor (NGF) expression in human glioma cells infected with human cytomegalovirus (HCMV). Methods U251 cells were cultured in RPMI 1640 culture medium and infected with HCMV AD 169 strain in vitro to establish a cell model of viral infection. Morphologic changes of U251 cells were observed under inverted microscope before and after infection with HCMV. Expression of NGF gene and protein of cells was detected by RT-PCR and Western blotting before and after infection with HCMV. Results The cytopathic effects of HCMV-infected cells appeared on day 5 after infection. However, differential NGF expression was evident on day 7. NGF expression was decreased significantly in U251 cells on day 7 after infection in comparison with control group (P〈0.05). Conclusion HCMV can down-regulate endogenous NGF levels in human glioma cell line U251.展开更多
HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infec...HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural precursor cell (NPCs) differentiation in vitro. Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. The identification and purity of the NPCs were confirmed by using immunofluorescence to detect the expression of the NPCs marker-Nestin. To drive NPCs differentiation, bFGF and EGF were withdrawn from the medium and replaced with FBS (10%). HCMV AD169 (MOI=5) was added into the differentiation medium at the onset of the differentiation. After 7 days of differentiation, in order to confirm whether NPCs are permissive for HCMV infection, immunofluorescence was used to stain for the presence of immediate early (IE) and late (pp65) HCMV proteins in the infected cells. The effects of HCMV infection on NPCs’ differentiation was observed by detecting the ratio of nestin and GFAP positive cells with confocal microscopy and immunofluorescence. The data showed that 95%±8% of the cells (passage 4-8) cultured were Nestin positive which suggested that majority of the cells were NPCs. On day 7 postinfection, most of the infected cells were IE and PP65 positive. The percentage of Nestin-positive cells were 93%±10% and 50%±19% (t=6.03, p<0.01) and those of GFAP-positive cells were 55±17% and 81%±11% (t=3.77, p<0.01) in HCMV treated and control groups respectively. These findings indicate that NPCs are HCMV permissive cells and HCMV (AD 169) infection suppresses the differentiation of Hippocampus-genetic human NPCs into astrocytes. These effects may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.展开更多
AIM:To develop a practical and reproducible rat model of hepatorenal syndrome for further study of the pathophysiology of human hepatorenal syndrome. METHODS:Sprague-Dawley rats were intravenously injected with D-gala...AIM:To develop a practical and reproducible rat model of hepatorenal syndrome for further study of the pathophysiology of human hepatorenal syndrome. METHODS:Sprague-Dawley rats were intravenously injected with D-galactosamine and lipopolysaccharide(LPS) via the tail vein to induce fulminant hepatic failure to develop a model of hepatorenal syndrome. Liver and kidney function tests and plasma cytokine levels were measured after D-galactosamine/LPS administration,and hepatic and renal pathology was studied. Glomerular filtration rate was detected in conscious rats using micro-osmotic pump technology with fluorescein isothiocyanate-labelled inulin as a surrogate marker.RESULTS:Serum levels of biochemical indicators including liver and kidney function indexes and cytokines all significantly changed,especially at 12 h after D-galactosamine/LPS administration [alanine aminotransferase,3389.5 ± 499.5 IU/L; blood urea nitrogen,13.9 ± 1.3 mmol/L; Cr,78.1 ± 2.9 μmol/L; K+,6.1 ± 0.5 mmol/L; Na+,130.9 ± 1.9 mmol/L; Cl-,90.2 ± 1.9 mmol/L; tumor necrosis factor-α,1699.6 ± 599.1 pg/m L; endothelin-1,95.9 ± 25.9 pg/m L; P < 0.05 compared with normal saline control group]. Hepatocyte necrosis was aggravated gradually,which was most significant at 12 h after treatment with D-galactosamine/LPS,and was characterized by massive hepatocyte necrosis,while the structures of glomeruli,proximal and distal tubules were normal. Glomerular filtration rate was significantly decreased to 30%-35% of the control group at 12 h after D-galactosamine/LPS administration [Glomerular filtration rate(GFR)1,0.79 ± 0.11 m L/min; GFR2,3.58 ± 0.49 m L/min·kg BW-1; GFR3,0.39 ± 0.99 m L/min·g KW-1]. The decreasing timing of GFR was consistent with that of the presence of hepatocyte necrosis and liver and kidney dysfunction.CONCLUSION:The joint use of D-galactosamine and LPS can induce liver and kidney dysfunction and decline of glomerular filtration rate in rats which is a successful rat model of hepatorenal syndrome.展开更多
AIM: To investigate the role of the duodenum in the regulation of plasma ghrelin levels and body mass index (BMI), and the correlation between them after subtotal gastrectomy. METHODS: Forty-two patients with T0-1N0-1...AIM: To investigate the role of the duodenum in the regulation of plasma ghrelin levels and body mass index (BMI), and the correlation between them after subtotal gastrectomy. METHODS: Forty-two patients with T0-1N0-1M0 gastric cancer were divided into two groups after gastrectomy according to digestive reconstruction pattern, Billroth Ⅰ group (n = 23) and Billroth Ⅱ group (n = 19). Ghrelin levels were determined with radioimmunoassay (RIA) before and on d 1, 7, 30 and 360 after gastrectomy, and BMI was also measured. RESULTS: The two groups had identical postoperative trends in ghrelin alterations during the early stage, both decreasing sharply to a nadir on d 1 (36.7% vs 35.7%), then markedly increasing on d 7 (51.0% vs 51.1%). On d 30, ghrelin levels in the Billroth Ⅰ group were slightly higher than those in the Billroth Ⅱ group. However, those of the Billroth Ⅰ group recovered to 93.6% on d 360, which approached, although lower than, the preoperative levels, and no statistically significant difference was observed. Those of the Billroth Ⅱ group recovered to only 81.6% and manifested significant discrepancy with preoperative levels (P = 0.033). Compared with preoperative levels, ghrelin levels of the two groups decreased by 6.9% and 18.4% and BMI fellby 3.3% and 6.4%, respectively. The linear regression correlations were revealed in both groups between decrease of ghrelin level and BMI (R12 = 0.297, P = 0.007; R22 = 0.559, P < 0.001).CONCLUSION: Anatomically and physiologically, the duodenum compensatively promotes ghrelin recovery and accordingly enhances BMI after gastrectomy. Regarding patients with insufficient ghrelin secretion, ghrelin is positively associated with BMI.展开更多
Combining adiabatic passage and Rydberg antiblockade, we propose a scheme to implement a two-qubit phase gate between two Rydberg atoms. Detuning parameters between frequencies of atomic transitions and those of the c...Combining adiabatic passage and Rydberg antiblockade, we propose a scheme to implement a two-qubit phase gate between two Rydberg atoms. Detuning parameters between frequencies of atomic transitions and those of the corresponding driving lasers are carefully chosen to offset the blockade effect of two Rydberg atoms, so that an effective Hamiltonian,representing a single-photon detuning L-type three-level system and concluding the quantum state of two Rydberg atoms excited simultaneously, is obtained. The adiabatic-passage technique, based on the effective Hamiltonian, is adopted to implement a two-atom phase gate by using two time-dependent Rabi frequencies. Numerical simulations indicate that a high-fidelity two-qubit p-phase gate is constructed and its operation time does not have to be controlled accurately. Besides,owing to the long coherence time of the Rydberg state, the phase gate is robust against atomic spontaneous emission.展开更多
This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with des...This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.展开更多
The rate constants of the reaction between hydroxyl radical (OH-) and dimethyl sulfide (DMS) were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O(3p) on ...The rate constants of the reaction between hydroxyl radical (OH-) and dimethyl sulfide (DMS) were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O(3p) on DMS consumption were found by the photolysis of HONO and CH3ONO as OH. sources, and the rate constants obtained in these systems varied significantly. The rate constants of the reaction between DMS and OH- (generated by photolysis of H2 O2) at room temperature were 8.56 × 10^-12, 11.31× 10^-12, and 4.50× 10^-12 cm3/(molecule.s), in air, O2, and N2, respectively. The temperature dependence of the rate constants for OH- with DMS over the temperature range of 287-338 K was also investigated in nitrogen and air, and the Arrhenius expression was obtained as follows: kaire=(7.24±0.28)× 10^-13exp[(770.7±E97.2)/T], kN2 =(3.40±0.15) × 10^-11 exp[-- (590.3±165.9)/T].展开更多
AIM To detect the expression of typeⅠ inositol 1,4,5-trisphosphate receptor(IP3 RI) in the kidney of rats with hepatorenal syndrome(HRS).METHODS One hundred and twenty-five Sprague-Dawley rats were randomly divided i...AIM To detect the expression of typeⅠ inositol 1,4,5-trisphosphate receptor(IP3 RI) in the kidney of rats with hepatorenal syndrome(HRS).METHODS One hundred and twenty-five Sprague-Dawley rats were randomly divided into four groups to receive an intravenous injection of D-galactosamine(D-Gal N) plus lipopolysaccharide(LPS; group G/L, n = 50), D-Gal N alone(group G, n = 25), LPS alone(group L, n = 25), and normal saline(group NS, n = 25), respectively.At 3, 6, 9, 12, and 24 h after injection, blood, liver, and kidney samples were collected. Hematoxylineosin staining of liver tissue was performed to assess hepatocyte necrosis. Electron microscopy was used to observe ultrastructural changes in the kidney. Western blot analysis and real-time PCR were performed to detect the expression of IP3 RI protein and m RNA in the kidney, respectively.RESULTS Hepatocyte necrosis was aggravated gradually, which was most significant at 12 h after treatment with D-galactosamine/lipopolysaccharide, and was characterized by massive hepatocyte necrosis. At the same time, serum levels of biochemical indicators including liver and kidney function indexes were all significantly changed. The structure of the renal glomerulus and tubules was normal at all time points. Western blot analysis indicated that IP3 RI protein expression began to rise at 3 h(P < 0.05) and peaked at 12 h(P < 0.01). Real-time PCR demonstrated that IP3 RI m RNA expression began to rise at 3 h(P < 0.05) and peaked at 9 h(P < 0.01).CONCLUSION IP3 RI protein expression is increased in the kidney of HRS rats, and may be regulated at the transcriptional level.展开更多
BACKGROUND Pneumonia of uncertain cause has been reported in Wuhan,China since the beginning of early December 2019.In early January 2020,a novel strain ofβ-coronavirus was identified by the Chinese Center for Diseas...BACKGROUND Pneumonia of uncertain cause has been reported in Wuhan,China since the beginning of early December 2019.In early January 2020,a novel strain ofβ-coronavirus was identified by the Chinese Center for Disease Control and Prevention from the pharyngeal swab specimens of patients,which was recently named severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).There is evidence of human-to-human transmission and familial cluster outbreak of SARSCoV-2 infection.The World Health Organization(WHO)recently declared the SARS-CoV-2 epidemic a global health emergency.As of February 17,2020,71329 laboratory-confirmed cases(in 25 countries,including the United States and Germany)have been reported globally.Other than its rapid transmission,the epidemiological and clinical characteristics of coronavirus disease 2019(COVID-19)remain unclear.In December 2019,coronavirus disease(named COVID-19 by the WHO)associated with the SARS-CoV-2 emerged in Wuhan,China and spread quickly across the country.AIM To analyze the epidemiological and clinical characteristics of confirmed cases of this disease in Liaoning province,a Chinese region about 1800 km north of Wuhan.METHODS The clinical data of 56 laboratory-confirmed COVID-19 cases due to 2019-nCoV infection were analyzed.The cases originated from eight cities in Liaoning province.RESULTS The median age of the patients was 45 years,and 57.1%of them were male.No patient had been in direct contact with wild animals.Among them,23 patients(41.1%)had resided in or traveled to Wuhan,27 cases(48.2%)had been in contact with confirmed COVID-19 patients,5 cases(8.9%)had been in contact with confirmed patients with a contact history to COVID-19 patients,and 1 case(1.8%)had no apparent history of exposure.Fever(75.0%)and cough(60.7%)were the most common symptoms.The typical manifestations in lung computed tomography(CT)included ground-glass opacity and patchy shadows,with 67.8%of them being bilateral.Among the patients in the cohort,78.6%showed reduction in their lymphocyte counts,57.1%showed increases in their C-reactive protein levels,and 50.0%showed decreases in their blood albumin levels.Eleven patients(19.6%)were admitted to intensive care unit,2 patients(3.5%)progressed to acute respiratory distress syndrome,4 patients(7.1%)were equipped with non-invasive mechanical ventilation,and 1 patient(1.8)received extracorporeal membrane oxygenation support.There were 5 mild cases(5/56,8.9%),40 moderate cases(40/56,71.4%),10 severe cases(10/56,17.9%),and 1 critical case(1/56,1.8%).No deaths were reported.CONCLUSION SARS-CoV-2 can be transmitted among humans.Most COVID-19 patients show symptoms of fever,cough,lymphocyte reduction,and typical lung CT manifestations.Most are moderate cases.The seriousness of the disease(as indicated by blood oxygen saturation,respiratory rate,oxygenation index,blood lymphocyte count,and lesions shown in lung CT)is related to history of living in or traveling to Wuhan,underlying diseases,admittance to intensive care unit,and mechanical ventilation.展开更多
Human cytomegalovirus (HCMV) is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of...Human cytomegalovirus (HCMV) is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of endogenic nerve growth factor expression in neuroglia ceils by HCMV infection. The results showed that basal, endogenous NGF expression in U251 was unchanged during early HCMV infection. NGF expression is strongly down-regulated during the latent phase of infection. These results suggest that HCMV can depress the NGF expression in U251 cells.展开更多
文摘BACKGROUND Magnetic resonance imaging(MRI)scanning with susceptibility weighted imaging(SWI)sequences plays a significant role in the diagnosis and prognostic evaluation of neonatal hypoxic-ischemic encephalopathy(HIE).AIM To observe the role of MRI multi-parameter quantitative indexes in the diagnosis of neonatal HIE.METHODS The imaging data from 23 cases of neonatal HIE admitted to the Imaging Department of Ganyu District People's Hospital of Lianyungang City and 23 neonates without HIE admitted during the same period were analyzed retrospectively from August,2021 to December,2023.The results of clinical judgment were compared with the results of computed tomography(CT)and MRI examinations.RESULTS The degree of cerebral edema(more than moderate),the number of damaged brain regions(>2),the number of cerebral hemorrhages(>2),and the percentage of small venous dilatation detected were higher in MRI than in CT examination,and the differences were statistically significant(P<0.05).The total area of the largest region of cerebral damage and of cerebral hemorrhage observed by MRI examination were significantly larger than those of CT examination(P<0.01).Multiparametric quantitative MRI combined with diffusion weighted imaging and SWI had higher sensitivity and accuracy than CT diagnosis,and the difference was statistically significant(P<0.05).The difference in the specificity of the two modes of diagnosis was not significant(P>0.05).CONCLUSION The use of MRI multi-parameter quantitative indexes can accurately diagnose and evaluate neonatal HIE.
基金The authors greatly thanked the financial support from the National Key Research and Development Program of China(funded by National Natural Science Foundation of China,No.2019YFA0708300)the Strategic Cooperation Technology Projects of CNPC and CUPB(funded by China National Petroleum Corporation,No.ZLZX2020-03)+1 种基金the National Science Fund for Distinguished Young Scholars(funded by National Natural Science Foundation of China,No.52125401)Science Foundation of China University of Petroleum,Beijing(funded by China University of petroleum,Beijing,No.2462022SZBH002).
文摘Accurate prediction of the rate of penetration(ROP)is significant for drilling optimization.While the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its credibility.This study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified Linear Unit(ReLU)activation function.By leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector operations.The FNN model is linearly characterized through further simplification,enabling its interpretation and analysis.The proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim Oilfield.The results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally well.The relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data similarity.In the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation equation.Furthermore,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well section.The established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.
基金supported by the National Natural Science Foundation of China(No.42374226)Natural Science Foundation of Jiangxi Province(Nos.20232BAB201043 and 20232BCJ23006)+1 种基金a sub-project of the nuclear energy development project of the China National Defense Science and Industry Bureau‘n-γfusion logging method theory research’(No.20201192-01)the Fundamental Science on Radioactive Geology and Exploration Technology Laboratory(No.2022RGET20)。
文摘A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide fuel.FH-NCM/S1 adopts an inte-grated approach,combining the shift register analysis mode with the pulse-position timestamp mode using an FPGA.The optimal effective length of the^(3)He neutron detector was determined to be 30 cm,and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP simulations.After fabricating the device,calibration measurements were per-formed using a^(252)Cf neutron source;a detection efficiency of 43.07%and detector die-away time of 55.79μs were observed.Nine samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity counter.The obtained double rates underwent corrections for detection efficiency(ε)and double gate fraction(f_(d)),resulting in corrected double rates(D_(c)),which were used to validate the accuracy of the shift register analysis mode.Furthermore,the device exhibited fluctuations in the measurement results,and within a single 20 s measurement,these fluctuations remained below 10%.After 30 cycles,the relative error in the mass of^(240)Pu was less than 5%.Finally,correlation calculations confirmed the robust consistency of both measurement modes.This study holds specific significance for the subsequent design and development of neutron multiplicity devices.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61505261,62101597,61605248,and 61675235)the National Key Research and Development Program of China (Grant No.2020YFA0309702)+2 种基金the China Postdoctoral Science Foundation (Grant No.2021M691536)the Natural Science Foundation of Henan Province,China (Grant Nos.202300410534 and 202300410532)the Fund of the Anhui Initiative in Quantum Information Technologies。
文摘The reference-frame-independent(RFI)quantum key distribution(QKD)is suitable for satellite-based links by removing the active alignment on the reference frames.However,how the beam wandering influences the performance of RFI-QKD remains a pending issue in satellite-to-ground links.In this paper,based on the mathematical model for characterizing beam wandering,we present the security analysis for satellite-to-ground RFI-QKD and analytically derive formulas for calculating the secret key rate with beam wandering.Our simulation results show that the performance of RFI-QKD is better than the Bennett–Brassard 1984(BB84)QKD with beam wandering in asymptotic case.Furthermore,the degree of influences of beam wandering is specifically presented for satellite-to-ground RFI-QKD when statistical fluctuations are taken into account.Our work can provide theoretical support for the realization of RFI-QKD using satellite-to-ground links and have implications for the construction of large-scale satellite-based quantum networks.
基金supported by the National Natural Science Foundation of China(Grant Nos.61505261,62101597,61605248,and 61675235)the National Key Research and Development Program of China(Grant No.2020YFA0309702)+2 种基金the China Postdoctoral Science Foundation(Grant No.2021M691536)the Natural Science Foundation of Henan Province(Grant Nos.202300410534 and 202300410532)the Anhui Initiative in Quantum Information Technologies.
文摘The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest.
基金financially supported by the National Natural Science Foundation of China (No.51777057)the Natural Science Foundation of Hebei Province, China (No.E2016202106)the Science and Technology Research Project of Colleges and Universities in Hebei Province, China (No.ZD2016078)
文摘AgSnO_ 2 electrical contact materials doped with Bi_2O_3,La_2O_3,and TiO_2 were successfully fabricated by the powder metallurgy method under different initial sintering temperatures.The electrical conductivity,density,hardness,and contact resistance of the Ag Sn O_2/Bi_2O_3,AgSnO_2/La_2O_3,and AgSnO_2/Ti O_2 contact materials were measured and analyzed.The arc-eroded surface morphologies of the doped AgSnO_2 contact materials were investigated by scanning electron microscopy(SEM).The effects of the initial sintering temperature on the physical properties and electrical contact properties of the doped AgSnO_2 contact materials were discussed.The results indicate that the physical properties can be improved and the contact resistance of the AgSnO_2 contact materials can be substantially reduced when the materials are sintered under their optimal initial sintering temperatures.
基金The authors thank and appreciate Qiu-li Li and Ke-jun Hou for their help in guiding the dating work.This study was supported by National Science Foundation of China(41425010,41430212)China Geological Survey Project(DD20190057)+1 种基金National Key Research and Development Project of China(2016YFC0600304)Basic scientific research fund in Institute of Geology,CAGS(J1901-1,J1901-10).
文摘A suite of ultramafic and mafic rocks developed in the Chigu Tso area,eastern Tethyan Himalaya.Baddeleyite and zircon U-Pb ages acquired by SIMS and LA-ICP-MS from olivine pyroxenite rocks in the Chigu Tso area are 138.9±3.0 Ma and 139.0±1.9 Ma,respectively.These two Early Cretaceous ages are similar with the ages of the more abundant mafic rocks in the eastern Tethyan Himalaya,indicating that this suite of ultramafic and mafic rocks in the Chigu Tso area should be included in the outcrop area of the Comei Large Igneous Province(LIP).These ultramafic rocks provide significant evidence that the involvement of mantle plume/hot spot activities in the formation of the Comei LIP.Baddeleyite U-Pb dating by SIMS is one reliable and convenient method to constrain the formation time of ultramafic rocks.The dating results of baddeleyite and zircon from the olivine pyroxenite samples in this paper are consistent with each other within analytical uncertainties,suggesting that baddeleyite and zircon were both formed during the same magmatic process.The consistency of baddeleyite U-Pb ages in the Chigu Tso area with zircon U-Pb ages for a large number of Early Cretaceous mafic rocks in the eastern Tethyan Himalaya further support that zircon grains from such mafic rocks yielding Early Cretaceous ages are also magmatic in origin.
基金supported by the National S&T Major Project (No.ZX069)
文摘The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reactor and steam generator modules with a thermal power of 250 MW_(th)and power generation of approximately 100 MW_(e)per module.Six modules in parallel,connected to a steam turbine,form a 600-MW_(e)nuclear power plant.In addition,its system configuration in the nuclear island is identical to that of the HTR-PM in which the technical risks are minimized.Under this principle,the HTR-PM600 achieves the same level of inherent safety as the HTR-PM.The concept of a ventilated lowpressure containment(VLPC)is unchanged;however,a large circular VLPC accommodating all six reactor modules is adopted rather than the previous small-cavity-type VLPC,which contains only one module,as defined for the HTR-PM.The layout of the nuclear island and its associated systems refer to single-unit pressurized water reactor(PWR)practices.With this layout,the HTR-PM600achieves a volume size of the nuclear island that is comparable to a domestic PWR of the same power level.This will be a GenerationⅣnuclear energy technology that is economically competitive.
基金supported by the National Natural Science Foundation of China, (No. 30770105)Mt. Tai Scholar Construction Engineering Special Foundation of Shandong Province
文摘Objective To explore the change of endogenic nerve growth factor (NGF) expression in human glioma cells infected with human cytomegalovirus (HCMV). Methods U251 cells were cultured in RPMI 1640 culture medium and infected with HCMV AD 169 strain in vitro to establish a cell model of viral infection. Morphologic changes of U251 cells were observed under inverted microscope before and after infection with HCMV. Expression of NGF gene and protein of cells was detected by RT-PCR and Western blotting before and after infection with HCMV. Results The cytopathic effects of HCMV-infected cells appeared on day 5 after infection. However, differential NGF expression was evident on day 7. NGF expression was decreased significantly in U251 cells on day 7 after infection in comparison with control group (P〈0.05). Conclusion HCMV can down-regulate endogenous NGF levels in human glioma cell line U251.
基金National Natural Science Foundation ofChina (30770105)Qingdao Technology Project (08-1-3-30-jch) Mt. Tai Scholar Construction Engineering Special Foundation of Shandong province, China.
文摘HCMV is a major cause of congenital brain disease in humans, and its neuropathogenesis is not yet fully understood. The objective of the present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural precursor cell (NPCs) differentiation in vitro. Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. The identification and purity of the NPCs were confirmed by using immunofluorescence to detect the expression of the NPCs marker-Nestin. To drive NPCs differentiation, bFGF and EGF were withdrawn from the medium and replaced with FBS (10%). HCMV AD169 (MOI=5) was added into the differentiation medium at the onset of the differentiation. After 7 days of differentiation, in order to confirm whether NPCs are permissive for HCMV infection, immunofluorescence was used to stain for the presence of immediate early (IE) and late (pp65) HCMV proteins in the infected cells. The effects of HCMV infection on NPCs’ differentiation was observed by detecting the ratio of nestin and GFAP positive cells with confocal microscopy and immunofluorescence. The data showed that 95%±8% of the cells (passage 4-8) cultured were Nestin positive which suggested that majority of the cells were NPCs. On day 7 postinfection, most of the infected cells were IE and PP65 positive. The percentage of Nestin-positive cells were 93%±10% and 50%±19% (t=6.03, p<0.01) and those of GFAP-positive cells were 55±17% and 81%±11% (t=3.77, p<0.01) in HCMV treated and control groups respectively. These findings indicate that NPCs are HCMV permissive cells and HCMV (AD 169) infection suppresses the differentiation of Hippocampus-genetic human NPCs into astrocytes. These effects may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.
文摘AIM:To develop a practical and reproducible rat model of hepatorenal syndrome for further study of the pathophysiology of human hepatorenal syndrome. METHODS:Sprague-Dawley rats were intravenously injected with D-galactosamine and lipopolysaccharide(LPS) via the tail vein to induce fulminant hepatic failure to develop a model of hepatorenal syndrome. Liver and kidney function tests and plasma cytokine levels were measured after D-galactosamine/LPS administration,and hepatic and renal pathology was studied. Glomerular filtration rate was detected in conscious rats using micro-osmotic pump technology with fluorescein isothiocyanate-labelled inulin as a surrogate marker.RESULTS:Serum levels of biochemical indicators including liver and kidney function indexes and cytokines all significantly changed,especially at 12 h after D-galactosamine/LPS administration [alanine aminotransferase,3389.5 ± 499.5 IU/L; blood urea nitrogen,13.9 ± 1.3 mmol/L; Cr,78.1 ± 2.9 μmol/L; K+,6.1 ± 0.5 mmol/L; Na+,130.9 ± 1.9 mmol/L; Cl-,90.2 ± 1.9 mmol/L; tumor necrosis factor-α,1699.6 ± 599.1 pg/m L; endothelin-1,95.9 ± 25.9 pg/m L; P < 0.05 compared with normal saline control group]. Hepatocyte necrosis was aggravated gradually,which was most significant at 12 h after treatment with D-galactosamine/LPS,and was characterized by massive hepatocyte necrosis,while the structures of glomeruli,proximal and distal tubules were normal. Glomerular filtration rate was significantly decreased to 30%-35% of the control group at 12 h after D-galactosamine/LPS administration [Glomerular filtration rate(GFR)1,0.79 ± 0.11 m L/min; GFR2,3.58 ± 0.49 m L/min·kg BW-1; GFR3,0.39 ± 0.99 m L/min·g KW-1]. The decreasing timing of GFR was consistent with that of the presence of hepatocyte necrosis and liver and kidney dysfunction.CONCLUSION:The joint use of D-galactosamine and LPS can induce liver and kidney dysfunction and decline of glomerular filtration rate in rats which is a successful rat model of hepatorenal syndrome.
基金The Research Foundation of Changzhou Health Bureau, No. WZ200708
文摘AIM: To investigate the role of the duodenum in the regulation of plasma ghrelin levels and body mass index (BMI), and the correlation between them after subtotal gastrectomy. METHODS: Forty-two patients with T0-1N0-1M0 gastric cancer were divided into two groups after gastrectomy according to digestive reconstruction pattern, Billroth Ⅰ group (n = 23) and Billroth Ⅱ group (n = 19). Ghrelin levels were determined with radioimmunoassay (RIA) before and on d 1, 7, 30 and 360 after gastrectomy, and BMI was also measured. RESULTS: The two groups had identical postoperative trends in ghrelin alterations during the early stage, both decreasing sharply to a nadir on d 1 (36.7% vs 35.7%), then markedly increasing on d 7 (51.0% vs 51.1%). On d 30, ghrelin levels in the Billroth Ⅰ group were slightly higher than those in the Billroth Ⅱ group. However, those of the Billroth Ⅰ group recovered to 93.6% on d 360, which approached, although lower than, the preoperative levels, and no statistically significant difference was observed. Those of the Billroth Ⅱ group recovered to only 81.6% and manifested significant discrepancy with preoperative levels (P = 0.033). Compared with preoperative levels, ghrelin levels of the two groups decreased by 6.9% and 18.4% and BMI fellby 3.3% and 6.4%, respectively. The linear regression correlations were revealed in both groups between decrease of ghrelin level and BMI (R12 = 0.297, P = 0.007; R22 = 0.559, P < 0.001).CONCLUSION: Anatomically and physiologically, the duodenum compensatively promotes ghrelin recovery and accordingly enhances BMI after gastrectomy. Regarding patients with insufficient ghrelin secretion, ghrelin is positively associated with BMI.
基金Project supported by the National Natural Science Foundation of China(Grant No.11464046)
文摘Combining adiabatic passage and Rydberg antiblockade, we propose a scheme to implement a two-qubit phase gate between two Rydberg atoms. Detuning parameters between frequencies of atomic transitions and those of the corresponding driving lasers are carefully chosen to offset the blockade effect of two Rydberg atoms, so that an effective Hamiltonian,representing a single-photon detuning L-type three-level system and concluding the quantum state of two Rydberg atoms excited simultaneously, is obtained. The adiabatic-passage technique, based on the effective Hamiltonian, is adopted to implement a two-atom phase gate by using two time-dependent Rabi frequencies. Numerical simulations indicate that a high-fidelity two-qubit p-phase gate is constructed and its operation time does not have to be controlled accurately. Besides,owing to the long coherence time of the Rydberg state, the phase gate is robust against atomic spontaneous emission.
基金supported by National High-tech R&D Program of China(No.2012AA050905)
文摘This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.
基金This work was supported by the National Natural Science Foundation of China (No.20677067 and No.20577064) and the National Basic Research Pro- gram of China (No.2005CB422201).
文摘The rate constants of the reaction between hydroxyl radical (OH-) and dimethyl sulfide (DMS) were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O(3p) on DMS consumption were found by the photolysis of HONO and CH3ONO as OH. sources, and the rate constants obtained in these systems varied significantly. The rate constants of the reaction between DMS and OH- (generated by photolysis of H2 O2) at room temperature were 8.56 × 10^-12, 11.31× 10^-12, and 4.50× 10^-12 cm3/(molecule.s), in air, O2, and N2, respectively. The temperature dependence of the rate constants for OH- with DMS over the temperature range of 287-338 K was also investigated in nitrogen and air, and the Arrhenius expression was obtained as follows: kaire=(7.24±0.28)× 10^-13exp[(770.7±E97.2)/T], kN2 =(3.40±0.15) × 10^-11 exp[-- (590.3±165.9)/T].
基金Supported by Natural Science Foundation of Liaoning Province,No.20170540826Science and Technology Program of Shenyang City,No.18-014-4-49Innovation Support Program of Shenyang City for Young and Middle-Aged Researchers,No.RC170051
文摘AIM To detect the expression of typeⅠ inositol 1,4,5-trisphosphate receptor(IP3 RI) in the kidney of rats with hepatorenal syndrome(HRS).METHODS One hundred and twenty-five Sprague-Dawley rats were randomly divided into four groups to receive an intravenous injection of D-galactosamine(D-Gal N) plus lipopolysaccharide(LPS; group G/L, n = 50), D-Gal N alone(group G, n = 25), LPS alone(group L, n = 25), and normal saline(group NS, n = 25), respectively.At 3, 6, 9, 12, and 24 h after injection, blood, liver, and kidney samples were collected. Hematoxylineosin staining of liver tissue was performed to assess hepatocyte necrosis. Electron microscopy was used to observe ultrastructural changes in the kidney. Western blot analysis and real-time PCR were performed to detect the expression of IP3 RI protein and m RNA in the kidney, respectively.RESULTS Hepatocyte necrosis was aggravated gradually, which was most significant at 12 h after treatment with D-galactosamine/lipopolysaccharide, and was characterized by massive hepatocyte necrosis. At the same time, serum levels of biochemical indicators including liver and kidney function indexes were all significantly changed. The structure of the renal glomerulus and tubules was normal at all time points. Western blot analysis indicated that IP3 RI protein expression began to rise at 3 h(P < 0.05) and peaked at 12 h(P < 0.01). Real-time PCR demonstrated that IP3 RI m RNA expression began to rise at 3 h(P < 0.05) and peaked at 9 h(P < 0.01).CONCLUSION IP3 RI protein expression is increased in the kidney of HRS rats, and may be regulated at the transcriptional level.
文摘BACKGROUND Pneumonia of uncertain cause has been reported in Wuhan,China since the beginning of early December 2019.In early January 2020,a novel strain ofβ-coronavirus was identified by the Chinese Center for Disease Control and Prevention from the pharyngeal swab specimens of patients,which was recently named severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).There is evidence of human-to-human transmission and familial cluster outbreak of SARSCoV-2 infection.The World Health Organization(WHO)recently declared the SARS-CoV-2 epidemic a global health emergency.As of February 17,2020,71329 laboratory-confirmed cases(in 25 countries,including the United States and Germany)have been reported globally.Other than its rapid transmission,the epidemiological and clinical characteristics of coronavirus disease 2019(COVID-19)remain unclear.In December 2019,coronavirus disease(named COVID-19 by the WHO)associated with the SARS-CoV-2 emerged in Wuhan,China and spread quickly across the country.AIM To analyze the epidemiological and clinical characteristics of confirmed cases of this disease in Liaoning province,a Chinese region about 1800 km north of Wuhan.METHODS The clinical data of 56 laboratory-confirmed COVID-19 cases due to 2019-nCoV infection were analyzed.The cases originated from eight cities in Liaoning province.RESULTS The median age of the patients was 45 years,and 57.1%of them were male.No patient had been in direct contact with wild animals.Among them,23 patients(41.1%)had resided in or traveled to Wuhan,27 cases(48.2%)had been in contact with confirmed COVID-19 patients,5 cases(8.9%)had been in contact with confirmed patients with a contact history to COVID-19 patients,and 1 case(1.8%)had no apparent history of exposure.Fever(75.0%)and cough(60.7%)were the most common symptoms.The typical manifestations in lung computed tomography(CT)included ground-glass opacity and patchy shadows,with 67.8%of them being bilateral.Among the patients in the cohort,78.6%showed reduction in their lymphocyte counts,57.1%showed increases in their C-reactive protein levels,and 50.0%showed decreases in their blood albumin levels.Eleven patients(19.6%)were admitted to intensive care unit,2 patients(3.5%)progressed to acute respiratory distress syndrome,4 patients(7.1%)were equipped with non-invasive mechanical ventilation,and 1 patient(1.8)received extracorporeal membrane oxygenation support.There were 5 mild cases(5/56,8.9%),40 moderate cases(40/56,71.4%),10 severe cases(10/56,17.9%),and 1 critical case(1/56,1.8%).No deaths were reported.CONCLUSION SARS-CoV-2 can be transmitted among humans.Most COVID-19 patients show symptoms of fever,cough,lymphocyte reduction,and typical lung CT manifestations.Most are moderate cases.The seriousness of the disease(as indicated by blood oxygen saturation,respiratory rate,oxygenation index,blood lymphocyte count,and lesions shown in lung CT)is related to history of living in or traveling to Wuhan,underlying diseases,admittance to intensive care unit,and mechanical ventilation.
基金National Natural Science Foundation of China (30770105)Mt. Tai Scholar Construction Engineering Special Foundation of Shandong province.
文摘Human cytomegalovirus (HCMV) is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of endogenic nerve growth factor expression in neuroglia ceils by HCMV infection. The results showed that basal, endogenous NGF expression in U251 was unchanged during early HCMV infection. NGF expression is strongly down-regulated during the latent phase of infection. These results suggest that HCMV can depress the NGF expression in U251 cells.