BACKGROUND Osteoporosis(OP)has become a major public health problem worldwide.Most OP treatments are based on the inhibition of bone resorption,and it is necessary to identify additional treatments aimed at enhancing ...BACKGROUND Osteoporosis(OP)has become a major public health problem worldwide.Most OP treatments are based on the inhibition of bone resorption,and it is necessary to identify additional treatments aimed at enhancing osteogenesis.In the bone marrow(BM)niche,bone mesenchymal stem cells(BMSCs)are exposed to a hypoxic environment.Recently,a few studies have demonstrated that hypoxiainducible factor 2alpha(HIF-2α)is involved in BMSC osteogenic differentiation,but the molecular mechanism involved has not been determined.AIM To investigate the effect of HIF-2αon the osteogenic and adipogenic differentiation of BMSCs and the hematopoietic function of hematopoietic stem cells(HSCs)in the BM niche on the progression of OP.METHODS Mice with BMSC-specific HIF-2αknockout(Prx1-Cre;Hif-2αfl/fl mice)were used for in vivo experiments.Bone quantification was performed on mice of two genotypes with three interventions:Bilateral ovariectomy,semilethal irradiation,and dexamethasone treatment.Moreover,the hematopoietic function of HSCs in the BM niche was compared between the two mouse genotypes.In vitro,the HIF-2αagonist roxadustat and the HIF-2αinhibitor PT2399 were used to investigate the function of HIF-2αin BMSC osteogenic and adipogenic differentiation.Finally,we investigated the effect of HIF-2αon BMSCs via treatment with the mechanistic target of rapamycin(mTOR)agonist MHY1485 and the mTOR inhibitor rapamycin.RESULTS The quantitative index determined by microcomputed tomography indicated that the femoral bone density of Prx1-Cre;Hif-2αfl/fl mice was lower than that of Hif-2αfl/fl mice under the three intervention conditions.In vitro,Hif-2αfl/fl mouse BMSCs were cultured and treated with the HIF-2αagonist roxadustat,and after 7 d of BMSC adipogenic differentiation,the oil red O staining intensity and mRNA expression levels of adipogenesis-related genes in BMSCs treated with roxadustat were decreased;in addition,after 14 d of osteogenic differentiation,BMSCs treated with roxadustat exhibited increased expression of osteogenesis-related genes.The opposite effects were shown for mouse BMSCs treated with the HIF-2αinhibitor PT2399.The mTOR inhibitor rapamycin was used to confirm that HIF-2αregulated BMSC osteogenic and adipogenic differentiation by inhibiting the mTOR pathway.Consequently,there was no significant difference in the hematopoietic function of HSCs between Prx1-Cre;Hif-2αfl/fl and Hif-2αfl/fl mice.CONCLUSION Our study showed that inhibition of HIF-2αdecreases bone mass by inhibiting the osteogenic differentiation and increasing the adipogenic differentiation of BMSCs through inhibition of mTOR signaling in the BM niche.展开更多
BACKGROUND There are many available treatment options for keloid;however,single treatments are usually less effective.Therefore,more scientifically rational and effective com-bined treatment methods should be sought t...BACKGROUND There are many available treatment options for keloid;however,single treatments are usually less effective.Therefore,more scientifically rational and effective com-bined treatment methods should be sought to solve the pain associated with keloids.AIM To explore the efficacy and safety of surgical resection and ultra-reduced tension suture combined with superficial radiation as keloid treatment.METHODS Fifteen keloid patients admitted to Qingdao Eighth People's Hospital from June 2020 to January 2022 were enrolled in this retrospective analysis.All patients underwent a comprehensive treatment approach comprising surgical resection,ultra-reduced tension suture incision,and superficial radiation therapy within 24 h postoperatively.The modified Vancouver Scar Scale(mVSS)and Patient and Observer Scar Assessment Scale(POSAS)were used to evaluate the treatment effect,whereas the efficacy,adverse effects,and recurrence rate were observed according to the 12-mo follow-up after treatment.RESULTS The mVSS and POSAS scores at 1 and 6 mo after combination treatment decreased compared to before treatment(P<0.001),and the overall response rate was 93.3%.Only one case recurred,yielding a 6.7%recurrence rate.The incidence of local chromour sedimentation rate in 1–3 mo after radiotherapy was 33.3%(5 patients),all subsiding after 6–9 mo,without complications,such as delayed wound healing or dermatitis.CONCLUSION Surgical resection,super subtraction sutures,and superficial radiotherapy are treatment methods with short courses,low recurrence rates,and good safety profiles.展开更多
With the impoundment of the Three Gorges Reservoir, algal blooms have been found in some tributaries. In this study, according to the theoretical analysis of the eutrophication mechanism in a river-type reservoir trib...With the impoundment of the Three Gorges Reservoir, algal blooms have been found in some tributaries. In this study, according to the theoretical analysis of the eutrophication mechanism in a river-type reservoir tributary, a one-dimensional eutrophication model was developed for the Xiangxi River tributary of the Three Gorges Reservoir, and the influence of hydrodynamic conditions on the primary growth rate of algae was investigated. Furthermore, numerical predictions of hydraulic variables and eutrophication factors, such as the concentration distribution of TP, TN, and Chl-a in the spatial and temporal domains, were carried out. Comparison of computation results of TP, TN, and Chl-a concentrations along the river in the spring of 2005 with experimental data demonstrates the validity of the model. The agreement between the computation results and the experimental data of TP and TN concentrations is better than the agreement between those of Chl-a concentration. The simulated results also show that the Chl-a concentration downstream is much higher than that in the upstream tributary, which potentially indicates the outbreak of algae in this area. Therefore, this study provides a feasible method of accurately predicting the state of eutrophication in river-type reservoirs and their tributaries.展开更多
AIM:To achieve a better understanding of the origination of neuroendocrine(NE)cells in gastric adenocarcinoma.METHODS:In this study,120 cases of gastric adenocarcinoma were obtained.First,frozen section-immunohistoche...AIM:To achieve a better understanding of the origination of neuroendocrine(NE)cells in gastric adenocarcinoma.METHODS:In this study,120 cases of gastric adenocarcinoma were obtained.First,frozen section-immunohistochemistrical samples were selected from a large quantity of neuroendocrine cells.Second,laser capture microdissection was used to get target cells from gastric adenocarcinoma and whole genome amplification was applied to get a large quantity of DNA for further study.Third,genome-wide microsatellite abnormalities[microsatellite instability(MSI),loss of heterozygosity (LOH)]and p53 mutation were detected by polymerase chain reaction(PCR)-single-strand conformation polymer-phism-silver staining and PCR-sequencing in order to identify the clonality of NE cells.RESULTS:The total incidence rate of MSI was 27.4%,while LOH was 17.9%.Ten cases had a highest concordance for the two types of cells.The other samples had similar microsatellite changes,except for cases 7 and10.Concordant p53 mutations exhibited in sample 4,14,21 and 27,and there were different mutations between two kinds of cells in case 7.In case 17,mutation took place only in adenocarcinoma cells.p53 mutation was closely related with degree of differentiation,tumor-node-metastasis stage,vessel invasion and lymph node metastasis.In brief,NE and adenocarcinoma cells showed the same MSI,LOH or p53 mutation in most cases(27/30).In the other three cases,different MSI,LOH or p53 mutation occurred.CONCLUSION:NE and the gastric adenocarcinoma cells may mainly derive from the same stem cells,but the remaining cases showing different origin needs further investigation.展开更多
BACKGROUND Glomus tumors(GTs)are rare mesenchymal neoplastic lesions derived from cells of the glomus body.GTs rarely occurs in the visceral organs,where there may be few or no glomus bodies,and the majority of GTs ar...BACKGROUND Glomus tumors(GTs)are rare mesenchymal neoplastic lesions derived from cells of the glomus body.GTs rarely occurs in the visceral organs,where there may be few or no glomus bodies,and the majority of GTs are benign,rarely demonstrating aggressive or malignant behavior and histological features.CASE SUMMARY We report a patient with malignant GTs of the intestinal ileum with multiorgan metastases who was admitted due to moderate anemia.Capsule endoscopy revealed a bleeding mass in the intestinal ileum,and the patient underwent segmental ileal resection through laparoscopic surgery.The histopathological and immunohistochemical diagnoses were consistent with malignant GT.Longterm follow-up showed that the GT had metastasized to multiple organs such as the colon,brain,and possibly the lung.CONCLUSION This case was characterized by the highest degree of malignancy and by multiorgan metastases,and it was the first case of intestinal GT uncovered by capsule endoscopy.展开更多
The effect of random waves on vertical plane turbulent jets is studied numerically and the mechanism behind the interaction of the jet and waves is analyzed. The large eddy simulation method is used and the σ-coordin...The effect of random waves on vertical plane turbulent jets is studied numerically and the mechanism behind the interaction of the jet and waves is analyzed. The large eddy simulation method is used and the σ-coordinate system is adopted. Turbulence is modeled by a dynamic coherent eddy model. The σ-coordinate transformation is introduced to map the irregular physical domain with a wavy free surface and an uneven bottom onto a regular computational domain. The fractional step method is used to solve the filtered Navier–Stokes equations. Results presented include the distribution of velocity, the decay law of the mean velocity along the jet axis, self-similar characteristics and volume flux per unit width. In particular, the role of coherent structures on the momentum transfer along the jet centerline and the jet instantaneous characteristics in JONSWAP waves are a special focus of this research. The numerical results obtained are of great theoretical importance in understanding the behavior of turbulent jets in random wave environments.展开更多
AIM: To elucidate the impact of hemodynamic parameters on ultrasonography and serum fibrosis markers for the assessment of liver fibrosis in the children with infant hepatitis syndrome (IHS). METHODS: Forty-one ch...AIM: To elucidate the impact of hemodynamic parameters on ultrasonography and serum fibrosis markers for the assessment of liver fibrosis in the children with infant hepatitis syndrome (IHS). METHODS: Forty-one children with IHS and 46 healthy infants were examined by ultrasonography, and several hemodynamic indices such as peak systolic velocity (PSV) and resistant index (RI) of proper hepatic artery (PHA) were measured. Serum fibrosis markers including hyaluronic acid (HA), pre-collagen type-Ⅲ (PC-Ⅲ), collagen type Ⅳ (C-Ⅳ), and laminin (LN) were assayed by radioimmunoassays. In children with IHS, liver tissues were obtained either by ultrasound-guided liver biopsy (n = 35) or in the course of operation (n = 6). The stages of hepatic fibrosis were scored as mild (S1 and S2), moderate (S3), or severe (S4) according to liver histological diagnosis. Multiple groups comparative and Spearman correlative analyses were carried out. RESULTS: Histopathologically, 39 children (95.1%) were found to have hepatic fibrosis, 12 of them stage Sl or S2, 12 stage S3, and 15 stage S4. PSV, RI of the PHA, and serum HA showed a consecutive increase from mild to severe hepatic fibrosis and a close positive correlation with hepatic fibrosis in IHS group (r = 0.717, 0.745 and 0.712, respectively, P = 0.001). The Doppler waveform of HV was also positively correlated with the degree of hepatic fibrosis in IHS group (r = 0.783, P 〈 0.001).CONCLUSION: Combination of ultrasonic studies on the hepatic hemodynamics with the evaluation of serum HA may provide an indicator for hepatic fibrosis in patients with IHS, This may be a useful noninvasive method for the diagnosis and evaluation of the prognosis of IHS.展开更多
Propylene molecule owns two active sites,the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of selectivity.In this work,the direct liquid-phase propylene aerobic epoxidation pro...Propylene molecule owns two active sites,the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of selectivity.In this work,the direct liquid-phase propylene aerobic epoxidation protocol by chloride manganese meso-tetraphenylporphyrin(MnTPPCl)was developed.The conversion of propylene was 12.7%,and the selectivity towards PO(propylene oxide)reached up to 80.5%.The formation of PO was attributed to the mechanism via high-valent Mn species,which was confirmed by means of in situ UV–vis spectrum.展开更多
BACKGROUND Multiple system atrophy(MSA) is a serious progressive neurodegenerative disease. Early diagnosis of MSA is very difficult, and diagnostic biomarkers are limited. Growth differentiation factor 15(GDF15) is i...BACKGROUND Multiple system atrophy(MSA) is a serious progressive neurodegenerative disease. Early diagnosis of MSA is very difficult, and diagnostic biomarkers are limited. Growth differentiation factor 15(GDF15) is involved in the differentiation and progression of the central nervous system, and is widely distributed in peripheral blood, which may be a novel biomarker for MSA.AIM To determine serum GDF15 levels, related factors and their potential diagnostic value in MSA patients, compared with Parkinson’s disease(PD) patients and healthy controls.METHODS A case-control study was conducted, including 49 MSA patients, 50 PD patients and 50 healthy controls. Serum GDF15 levels were measured by human enzymelinked immunosorbent assay, and the differences between the MSA, PD and control groups were analyzed. Further investigations were performed in different MSA subgroups according to age of onset, sex, clinical subtypes, diagnostic criteria, and disease duration. Receiver-operating characteristic curve analysiswas used to evaluate the diagnostic value of GDF15, especially for the differential diagnosis between MSA and PD.RESULTS Serum GDF15 levels were significantly higher in MSA patients than in PD patients and healthy controls(P = 0.000). Males and those with a disease duration of more than three years showed higher serum GDF15 levels(P = 0.043 and 0.000;respectively). Serum GDF15 levels may be a potential diagnostic biomarker for MSA patients compared with healthy controls and PD patients(cutoff: 470.42 pg/m L, sensitivity: 85.7%, specificity: 88.0%;cutoff: 1075.91 pg/m L, sensitivity:51.0%, specificity: 96.0%;respectively).CONCLUSION Serum GDF15 levels are significantly higher in MSA patients and provide suggestions on the etiology of MSA.展开更多
A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface...A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface modification due to the inherent chemical activity. The structure and nature of Pt/CNx were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy spectrum. All the experimental results revealed that the large amount of doped nitrogen atoms in CNx was virtually effective for capturing the Pt(IV) ions. The improved surface nitrogen functionalities and hydrophilicity contributed to the good dispersion and immobi- lization of Pt nanoparticles on the CNx surface. The Pt/CNx served as active and reusable catalysts in the hydrogenation of allyl alcohol. This could be attributed to high dispersion of Pt nanoparticles and stronger interaction between Pt and the supports, which prevented the Pt nanoparticles from aggregating into less active Pt black and from leaching as well.展开更多
Compound open channel flows appear in most natural rivers are of great importance in river management and flood control.In this study,large eddy simulations were carried out to simulate the compound open channel flows...Compound open channel flows appear in most natural rivers are of great importance in river management and flood control.In this study,large eddy simulations were carried out to simulate the compound open channel flows with four different depth ratios(hr=0.10,0.25,0.50,and 0.75).The main flow velocity,secondary flow,Reynolds stress,and bed shear stress were obtained from numerical simulations.The depth-averaged stream wise momentum equation was used to quantify the lateral momentum exchange between the main channel and floodplain.The instantaneous coherent structures were presented by the Q criterion method.The impact of hr on flow structure and turbulence charac-teristics was analyzed.The results showed that with the increase of hr,the high velocity area in the main channel shifted to the floodplain,and the dip phenomenon became more obvious;the Reynolds stress largely contributed to the lateral momentum exchange within the flows near the side walls of floodplain;and the vortex structures were found to significantly increase in the floodplain region.展开更多
The number of films is numerous and the film contents are complex over the Internet and multimedia sources. It is time consuming for a viewer to select a favorite film. This paper presents an automatic recognition sys...The number of films is numerous and the film contents are complex over the Internet and multimedia sources. It is time consuming for a viewer to select a favorite film. This paper presents an automatic recognition system of film types. Initially, a film is firstly sampled as frame sequences. The color space, including hue, saturation,and brightness value(HSV), is analyzed for each sampled frame by computing the deviation and mean of HSV for each film. These features are utilized as inputs to a deep-learning neural network(DNN) for the recognition of film types. One hundred films are utilized to train and validate the model parameters of DNN. In the testing phase, a film is recognized as one of the five categories, including action, comedy, horror thriller, romance, and science fiction, by the trained DNN. The experimental results reveal that the film types can be effectively recognized by the proposed approach, enabling the viewer to select an interesting film accurately and quickly.展开更多
A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conv...A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size,the considerable advantages in much lower asymptotic frequency with tight field confinement,which enable the proposed filter to be more miniaturization.A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths.The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric,while the high-frequency cutoff band is realized by the proposed SSPPs structure.The influence of dispersion relation,electric field distribution,surface current,and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain(FDTD).To validate the design concept,the prototype of the miniaturized SSPPs BPF has been manufactured and measured.The experimental results show high performance of the fabricated sample,in which the working in a range of 0.9 GHz-5.2 GHz with the relative bandwidth is 142%,the insertion loss less than 0.5 dB,the reflection coefficient less than-10 dB,and the group delay is less than one ns.This works provides a mirror for realizing the miniaturization of waveguides,and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.展开更多
An ultra-wideband bandpass filter(BPF)with a wide out-of-band rejection based on a surface plasmonic waveguide(SPW)slotline with ring grooves is designed and analyzed.A paired microstrip-to-slotline transition is desi...An ultra-wideband bandpass filter(BPF)with a wide out-of-band rejection based on a surface plasmonic waveguide(SPW)slotline with ring grooves is designed and analyzed.A paired microstrip-to-slotline transition is designed for quasiTEM to TM mode conversion by using a microstrip line with a circular pad and the slotline with the same circular slot.The mode conversion between the TM and the surface plasmon polariton(SPP)mode is realized by using a gradient slotline with ring grooves and an impedance matching technique.The upper cut-off frequencies of the passband can be adjusted by using these proposed SPP units,while the lower frequencies of the passband are created by using the microstrip-toslotline transitions to give an ultra-wideband BPF.The dispersion curves of SPP units,electric field distribution,and the transmission spectra of the proposed ultra-wideband bandpass filter are all calculated and analyzed by the finite-difference time-domain(FDTD)method.The simulated results show that the presented filter has good performance including a wide3-dB bandwidth of 149%from 0.57 GHz to 3.93 GHz,an extremely wide 40-dB upper-band rejection from 4.2 GHz to18.5 GHz,and low loss and high selectivity in the passband.To prove the design validity,a prototype of the BPF has been manufactured and measured,showing a reasonable agreement with simulation results.The unique features of the proposed BPF may make it applicable for integrated circuit and plasmonic devices in microwave or THz frequency ranges.展开更多
Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes (N-S) equations were numerically solved with the fracti...Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes (N-S) equations were numerically solved with the fractional-step method in sigma coordinates. The subgrid-scale turbulent stress was modeled with a dynamic coherent eddy viscosity model proposed by the authors The computed velocity profiles are in good agreement with the available experimental results. The mean velocity and the turbulent Reynolds stress affected by a series of dune-shaped structures were compared and analyzed. The variation of turbulence statistics along the flow direction affected by the wavy bottom roughness has been studied. The turbulent boundary layer in a complex geographic environment can be simulated well with the proposed large eddy simulation (LES) model.展开更多
Images are generally corrupted by impulse noise during acquisition and transmission.Noise deteriorates the quality of images.To remove corruption noise,we propose a hybrid approach to restoring a random noisecorrupted...Images are generally corrupted by impulse noise during acquisition and transmission.Noise deteriorates the quality of images.To remove corruption noise,we propose a hybrid approach to restoring a random noisecorrupted image,including a block matching 3D(BM3D)method,an adaptive non-local mean(ANLM)scheme,and the K-singular value decomposition(K-SVD)algorithm.In the proposed method,we employ the morphological component analysis(MCA)to decompose an image into the texture,structure,and edge parts.Then,the BM3D method,ANLM scheme,and K-SVD algorithm are utilized to eliminate noise in the texture,structure,and edge parts of the image,respectively.Experimental results show that the proposed approach can effectively remove interference random noise in different parts;meanwhile,the deteriorated image is able to be reconstructed well.展开更多
BACKGROUND Previous studies have shown that diabetes mellitus is a common comorbidity of coronavirus disease 2019(COVID-19),but the effects of diabetes or anti-diabetic medication on the mortality of COVID-19 have not...BACKGROUND Previous studies have shown that diabetes mellitus is a common comorbidity of coronavirus disease 2019(COVID-19),but the effects of diabetes or anti-diabetic medication on the mortality of COVID-19 have not been well described.AIM To investigate the outcome of different statuses(with or without comorbidity)and anti-diabetic medication use before admission of diabetic after COVID-19.METHODS In this multicenter and retrospective study,we enrolled 1422 consecutive hospitalized patients from January 21,2020,to March 25,2020,at six hospitals in Hubei Province,China.The primary endpoint was in-hospital mortality.Epidemiological material,demographic information,clinical data,laboratory parameters,radiographic characteristics,treatment and outcome were extracted from electronic medical records using a standardized data collection form.Most of the laboratory data except fasting plasma glucose(FPG)were obtained in first hospitalization,and FPG was collected in the next day morning.Major clinical symptoms,vital signs at admission and comorbidities were collected.The treatment data included not only COVID-19 but also diabetes mellitus.The duration from the onset of symptoms to admission,illness severity,intensive care unit(ICU)admission,and length of hospital stay were also recorded.All data were checked by a team of sophisticated physicians.RESULTS Patients with diabetes were 10 years older than non-diabetic patients[(39-64)vs(56-70),P<0.001]and had a higher prevalence of comorbidities such as hypertension(55.5%vs 21.4%,P<0.001),coronary heart disease(CHD)(9.9%vs 3.5%,P<0.001),cerebrovascular disease(CVD)(3%vs 2.2%,P<0.001),and chronic kidney disease(CKD)(4.7%vs 1.5%,P=0.007).Mortality(13.6%vs 7.2%,P=0.003)was more prevalent among the diabetes group.Further analysis revealed that patients with diabetes who took acarbose had a lower mortality rate(2.2%vs 26.1,P<0.01).Multivariable Cox regression showed that male sex[hazard ratio(HR)2.59(1.68-3.99),P<0.001],hypertension[HR 1.75(1.18-2.60),P=0.006),CKD[HR 4.55(2.52-8.20),P<0.001],CVD[HR 2.35(1.27-4.33),P=0.006],and age were risk factors for the COVID-19 mortality.Higher HRs were noted in those aged≥65(HR 11.8[4.6-30.2],P<0.001)vs 50-64 years(HR 5.86[2.27-15.12],P<0.001).The survival curve revealed that,compared with the diabetes only group,the mortality was increased in the diabetes with comorbidities group(P=0.009)but was not significantly different from the noncomorbidity group(P=0.59).CONCLUSION Patients with diabetes had worse outcomes when suffering from COVID-19;however,the outcome was not associated with diabetes itself but with comorbidities.Furthermore,acarbose could reduce the mortality in diabetic.展开更多
This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder.A mathematical model of numerical wave tank with two-way fluid-solid interactions were d...This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder.A mathematical model of numerical wave tank with two-way fluid-solid interactions were developed and validated.The wave-induced vibrations of a single-degree-of-freedom cylinder were simulated at eleven gap ratios(d/a=8,10,12,14,16,18,20,22,24,28 and 32).Numerical results indicate that significant nonlinear characteristics are introduced into the originally linear waves with the presence of cylinder.Based on the variation characteristics of cylinder vibration amplitude,the gap ratios can be divided into three ranges,i.e.,the uncertain range(8≤d/a≤14),quasi-linear range(14≤d/a≤20)and linear range(20≤d/a≤32).Under the same wave condition,the gap ratio does not affect the frequencies of vortex shedding and cylinder vibration.The presence of the cylinder complicates the flow field and suppress the vortex shedding around the cylinder.展开更多
Near-field coupled plasmonic systems generally achieve plasmonically induced transparency(PIT) using only one-way bright–dark mode coupling. However, it is challenging to realize such well-designed devices,mainly bec...Near-field coupled plasmonic systems generally achieve plasmonically induced transparency(PIT) using only one-way bright–dark mode coupling. However, it is challenging to realize such well-designed devices,mainly because they depend significantly on the polarization direction. We exploit surface plasmons supported by two crossed layers of graphene nanoribbons(GNRs) to achieve dynamically tunable PIT, where each GNR operates as both the bright and dark modes simultaneously. The proposed PIT can result from either one-way bright–dark mode interactions or bidirectional bright–bright and bright–dark mode hybridized coupling when the polarization is perpendicular/parallel or at an angle to the GNRs, respectively.Additionally, identical ribbon widths yield polarization-insensitive single-window PIT, whereas different ribbon widths produce polarization-dependent double-window PIT. We examine the proposed technique using plasmon wave functions and the transfer matrix method; analytical and numerical results show excellent agreement. This study can provide physical insight into the PIT coupling mechanisms and advance the applicability and versatility of PIT-based sensing platforms and other active devices.展开更多
基金Supported by Basic and Applied Basic Research Foundation of Guangdong Province,No.2020A1515010123 and No.2021A1515010695Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province,No.2019A030317011.
文摘BACKGROUND Osteoporosis(OP)has become a major public health problem worldwide.Most OP treatments are based on the inhibition of bone resorption,and it is necessary to identify additional treatments aimed at enhancing osteogenesis.In the bone marrow(BM)niche,bone mesenchymal stem cells(BMSCs)are exposed to a hypoxic environment.Recently,a few studies have demonstrated that hypoxiainducible factor 2alpha(HIF-2α)is involved in BMSC osteogenic differentiation,but the molecular mechanism involved has not been determined.AIM To investigate the effect of HIF-2αon the osteogenic and adipogenic differentiation of BMSCs and the hematopoietic function of hematopoietic stem cells(HSCs)in the BM niche on the progression of OP.METHODS Mice with BMSC-specific HIF-2αknockout(Prx1-Cre;Hif-2αfl/fl mice)were used for in vivo experiments.Bone quantification was performed on mice of two genotypes with three interventions:Bilateral ovariectomy,semilethal irradiation,and dexamethasone treatment.Moreover,the hematopoietic function of HSCs in the BM niche was compared between the two mouse genotypes.In vitro,the HIF-2αagonist roxadustat and the HIF-2αinhibitor PT2399 were used to investigate the function of HIF-2αin BMSC osteogenic and adipogenic differentiation.Finally,we investigated the effect of HIF-2αon BMSCs via treatment with the mechanistic target of rapamycin(mTOR)agonist MHY1485 and the mTOR inhibitor rapamycin.RESULTS The quantitative index determined by microcomputed tomography indicated that the femoral bone density of Prx1-Cre;Hif-2αfl/fl mice was lower than that of Hif-2αfl/fl mice under the three intervention conditions.In vitro,Hif-2αfl/fl mouse BMSCs were cultured and treated with the HIF-2αagonist roxadustat,and after 7 d of BMSC adipogenic differentiation,the oil red O staining intensity and mRNA expression levels of adipogenesis-related genes in BMSCs treated with roxadustat were decreased;in addition,after 14 d of osteogenic differentiation,BMSCs treated with roxadustat exhibited increased expression of osteogenesis-related genes.The opposite effects were shown for mouse BMSCs treated with the HIF-2αinhibitor PT2399.The mTOR inhibitor rapamycin was used to confirm that HIF-2αregulated BMSC osteogenic and adipogenic differentiation by inhibiting the mTOR pathway.Consequently,there was no significant difference in the hematopoietic function of HSCs between Prx1-Cre;Hif-2αfl/fl and Hif-2αfl/fl mice.CONCLUSION Our study showed that inhibition of HIF-2αdecreases bone mass by inhibiting the osteogenic differentiation and increasing the adipogenic differentiation of BMSCs through inhibition of mTOR signaling in the BM niche.
基金This study was reviewed and approved by the Ethics Committee of Qingdao Eighth People’s Hospital(Approval no.:QBYLL-KY-2023-013).
文摘BACKGROUND There are many available treatment options for keloid;however,single treatments are usually less effective.Therefore,more scientifically rational and effective com-bined treatment methods should be sought to solve the pain associated with keloids.AIM To explore the efficacy and safety of surgical resection and ultra-reduced tension suture combined with superficial radiation as keloid treatment.METHODS Fifteen keloid patients admitted to Qingdao Eighth People's Hospital from June 2020 to January 2022 were enrolled in this retrospective analysis.All patients underwent a comprehensive treatment approach comprising surgical resection,ultra-reduced tension suture incision,and superficial radiation therapy within 24 h postoperatively.The modified Vancouver Scar Scale(mVSS)and Patient and Observer Scar Assessment Scale(POSAS)were used to evaluate the treatment effect,whereas the efficacy,adverse effects,and recurrence rate were observed according to the 12-mo follow-up after treatment.RESULTS The mVSS and POSAS scores at 1 and 6 mo after combination treatment decreased compared to before treatment(P<0.001),and the overall response rate was 93.3%.Only one case recurred,yielding a 6.7%recurrence rate.The incidence of local chromour sedimentation rate in 1–3 mo after radiotherapy was 33.3%(5 patients),all subsiding after 6–9 mo,without complications,such as delayed wound healing or dermatitis.CONCLUSION Surgical resection,super subtraction sutures,and superficial radiotherapy are treatment methods with short courses,low recurrence rates,and good safety profiles.
基金supported by the National Natural Science Foundation of China (Grant No. 50779028)the National Science and Technology Supporting Plan (Grant No. 2008BAB29B09)
文摘With the impoundment of the Three Gorges Reservoir, algal blooms have been found in some tributaries. In this study, according to the theoretical analysis of the eutrophication mechanism in a river-type reservoir tributary, a one-dimensional eutrophication model was developed for the Xiangxi River tributary of the Three Gorges Reservoir, and the influence of hydrodynamic conditions on the primary growth rate of algae was investigated. Furthermore, numerical predictions of hydraulic variables and eutrophication factors, such as the concentration distribution of TP, TN, and Chl-a in the spatial and temporal domains, were carried out. Comparison of computation results of TP, TN, and Chl-a concentrations along the river in the spring of 2005 with experimental data demonstrates the validity of the model. The agreement between the computation results and the experimental data of TP and TN concentrations is better than the agreement between those of Chl-a concentration. The simulated results also show that the Chl-a concentration downstream is much higher than that in the upstream tributary, which potentially indicates the outbreak of algae in this area. Therefore, this study provides a feasible method of accurately predicting the state of eutrophication in river-type reservoirs and their tributaries.
基金Supported by The Natural Science Foundation of Zhejiang ProvinceChina+2 种基金No.Y2110133the Zhejiang Provincial Medical Science Research FoundationNo.2010KYA060
文摘AIM:To achieve a better understanding of the origination of neuroendocrine(NE)cells in gastric adenocarcinoma.METHODS:In this study,120 cases of gastric adenocarcinoma were obtained.First,frozen section-immunohistochemistrical samples were selected from a large quantity of neuroendocrine cells.Second,laser capture microdissection was used to get target cells from gastric adenocarcinoma and whole genome amplification was applied to get a large quantity of DNA for further study.Third,genome-wide microsatellite abnormalities[microsatellite instability(MSI),loss of heterozygosity (LOH)]and p53 mutation were detected by polymerase chain reaction(PCR)-single-strand conformation polymer-phism-silver staining and PCR-sequencing in order to identify the clonality of NE cells.RESULTS:The total incidence rate of MSI was 27.4%,while LOH was 17.9%.Ten cases had a highest concordance for the two types of cells.The other samples had similar microsatellite changes,except for cases 7 and10.Concordant p53 mutations exhibited in sample 4,14,21 and 27,and there were different mutations between two kinds of cells in case 7.In case 17,mutation took place only in adenocarcinoma cells.p53 mutation was closely related with degree of differentiation,tumor-node-metastasis stage,vessel invasion and lymph node metastasis.In brief,NE and adenocarcinoma cells showed the same MSI,LOH or p53 mutation in most cases(27/30).In the other three cases,different MSI,LOH or p53 mutation occurred.CONCLUSION:NE and the gastric adenocarcinoma cells may mainly derive from the same stem cells,but the remaining cases showing different origin needs further investigation.
基金Supported by the National Natural Science Foundation of China,No.81900505
文摘BACKGROUND Glomus tumors(GTs)are rare mesenchymal neoplastic lesions derived from cells of the glomus body.GTs rarely occurs in the visceral organs,where there may be few or no glomus bodies,and the majority of GTs are benign,rarely demonstrating aggressive or malignant behavior and histological features.CASE SUMMARY We report a patient with malignant GTs of the intestinal ileum with multiorgan metastases who was admitted due to moderate anemia.Capsule endoscopy revealed a bleeding mass in the intestinal ileum,and the patient underwent segmental ileal resection through laparoscopic surgery.The histopathological and immunohistochemical diagnoses were consistent with malignant GT.Longterm follow-up showed that the GT had metastasized to multiple organs such as the colon,brain,and possibly the lung.CONCLUSION This case was characterized by the highest degree of malignancy and by multiorgan metastases,and it was the first case of intestinal GT uncovered by capsule endoscopy.
基金supported by the National Natural Science Foundation of China (50679023, 50879019)Ph.D. Programs Foundation of Ministry of Education of China (20070294012)+2 种基金the National Science Fund for Distinguished Young Scholars (50925932)Outstanding Doctoral Dissertation Incubation Program of Hohai University (2010B18814)Qing Lan Project of Jiangsu Province, and 333 High-Level Talent Training Program of Jiangsu Province (2017-B08038)
文摘The effect of random waves on vertical plane turbulent jets is studied numerically and the mechanism behind the interaction of the jet and waves is analyzed. The large eddy simulation method is used and the σ-coordinate system is adopted. Turbulence is modeled by a dynamic coherent eddy model. The σ-coordinate transformation is introduced to map the irregular physical domain with a wavy free surface and an uneven bottom onto a regular computational domain. The fractional step method is used to solve the filtered Navier–Stokes equations. Results presented include the distribution of velocity, the decay law of the mean velocity along the jet axis, self-similar characteristics and volume flux per unit width. In particular, the role of coherent structures on the momentum transfer along the jet centerline and the jet instantaneous characteristics in JONSWAP waves are a special focus of this research. The numerical results obtained are of great theoretical importance in understanding the behavior of turbulent jets in random wave environments.
基金Supported by the Bureau of Education, Guangxi ZhuangAutonomous Region, China, No. A9909
文摘AIM: To elucidate the impact of hemodynamic parameters on ultrasonography and serum fibrosis markers for the assessment of liver fibrosis in the children with infant hepatitis syndrome (IHS). METHODS: Forty-one children with IHS and 46 healthy infants were examined by ultrasonography, and several hemodynamic indices such as peak systolic velocity (PSV) and resistant index (RI) of proper hepatic artery (PHA) were measured. Serum fibrosis markers including hyaluronic acid (HA), pre-collagen type-Ⅲ (PC-Ⅲ), collagen type Ⅳ (C-Ⅳ), and laminin (LN) were assayed by radioimmunoassays. In children with IHS, liver tissues were obtained either by ultrasound-guided liver biopsy (n = 35) or in the course of operation (n = 6). The stages of hepatic fibrosis were scored as mild (S1 and S2), moderate (S3), or severe (S4) according to liver histological diagnosis. Multiple groups comparative and Spearman correlative analyses were carried out. RESULTS: Histopathologically, 39 children (95.1%) were found to have hepatic fibrosis, 12 of them stage Sl or S2, 12 stage S3, and 15 stage S4. PSV, RI of the PHA, and serum HA showed a consecutive increase from mild to severe hepatic fibrosis and a close positive correlation with hepatic fibrosis in IHS group (r = 0.717, 0.745 and 0.712, respectively, P = 0.001). The Doppler waveform of HV was also positively correlated with the degree of hepatic fibrosis in IHS group (r = 0.783, P 〈 0.001).CONCLUSION: Combination of ultrasonic studies on the hepatic hemodynamics with the evaluation of serum HA may provide an indicator for hepatic fibrosis in patients with IHS, This may be a useful noninvasive method for the diagnosis and evaluation of the prognosis of IHS.
基金financially supported by the National Key Research and Development Program of China (2020YFA0210900)the National Natural Science Foundation of China (No. 21938001 and 21878344)Research and Innovation Team Construction Project of Guangdong University of Petrochemical Technology
文摘Propylene molecule owns two active sites,the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of selectivity.In this work,the direct liquid-phase propylene aerobic epoxidation protocol by chloride manganese meso-tetraphenylporphyrin(MnTPPCl)was developed.The conversion of propylene was 12.7%,and the selectivity towards PO(propylene oxide)reached up to 80.5%.The formation of PO was attributed to the mechanism via high-valent Mn species,which was confirmed by means of in situ UV–vis spectrum.
基金Supported by National Natural Science Foundation of China,No.81771373Key Research and Development Plan of Zibo City,No.2019ZC010169 and No.2019ZC010166.
文摘BACKGROUND Multiple system atrophy(MSA) is a serious progressive neurodegenerative disease. Early diagnosis of MSA is very difficult, and diagnostic biomarkers are limited. Growth differentiation factor 15(GDF15) is involved in the differentiation and progression of the central nervous system, and is widely distributed in peripheral blood, which may be a novel biomarker for MSA.AIM To determine serum GDF15 levels, related factors and their potential diagnostic value in MSA patients, compared with Parkinson’s disease(PD) patients and healthy controls.METHODS A case-control study was conducted, including 49 MSA patients, 50 PD patients and 50 healthy controls. Serum GDF15 levels were measured by human enzymelinked immunosorbent assay, and the differences between the MSA, PD and control groups were analyzed. Further investigations were performed in different MSA subgroups according to age of onset, sex, clinical subtypes, diagnostic criteria, and disease duration. Receiver-operating characteristic curve analysiswas used to evaluate the diagnostic value of GDF15, especially for the differential diagnosis between MSA and PD.RESULTS Serum GDF15 levels were significantly higher in MSA patients than in PD patients and healthy controls(P = 0.000). Males and those with a disease duration of more than three years showed higher serum GDF15 levels(P = 0.043 and 0.000;respectively). Serum GDF15 levels may be a potential diagnostic biomarker for MSA patients compared with healthy controls and PD patients(cutoff: 470.42 pg/m L, sensitivity: 85.7%, specificity: 88.0%;cutoff: 1075.91 pg/m L, sensitivity:51.0%, specificity: 96.0%;respectively).CONCLUSION Serum GDF15 levels are significantly higher in MSA patients and provide suggestions on the etiology of MSA.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.21101105 and No.51174274), Innovation Program supported by Shanghai Municipal Education Commission (No.12ZZ195 and No.13YZ134), Shanghai Educational Development Foundation and the Shanghai Municipal Education Commission (No.12CG66), "Shu Guang" Project supported by Shanghai Municipal Education Commission (No.09SG54), and Shanghai Municipal Natural Science Foundation (No.13ZR1454800).
文摘A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface modification due to the inherent chemical activity. The structure and nature of Pt/CNx were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy spectrum. All the experimental results revealed that the large amount of doped nitrogen atoms in CNx was virtually effective for capturing the Pt(IV) ions. The improved surface nitrogen functionalities and hydrophilicity contributed to the good dispersion and immobi- lization of Pt nanoparticles on the CNx surface. The Pt/CNx served as active and reusable catalysts in the hydrogenation of allyl alcohol. This could be attributed to high dispersion of Pt nanoparticles and stronger interaction between Pt and the supports, which prevented the Pt nanoparticles from aggregating into less active Pt black and from leaching as well.
基金supported by the Fundamental Research Funds for the Central Universities(Grants No.B200202116 and B200204044)the National Natural Science Foundation of China(Grant No.51879086)the 111 Project from the Minstry of Education and State Administration of Foreign Expert Affairs of China(Grant No.B17015).
文摘Compound open channel flows appear in most natural rivers are of great importance in river management and flood control.In this study,large eddy simulations were carried out to simulate the compound open channel flows with four different depth ratios(hr=0.10,0.25,0.50,and 0.75).The main flow velocity,secondary flow,Reynolds stress,and bed shear stress were obtained from numerical simulations.The depth-averaged stream wise momentum equation was used to quantify the lateral momentum exchange between the main channel and floodplain.The instantaneous coherent structures were presented by the Q criterion method.The impact of hr on flow structure and turbulence charac-teristics was analyzed.The results showed that with the increase of hr,the high velocity area in the main channel shifted to the floodplain,and the dip phenomenon became more obvious;the Reynolds stress largely contributed to the lateral momentum exchange within the flows near the side walls of floodplain;and the vortex structures were found to significantly increase in the floodplain region.
基金supported by MOST under Grant No.MOST 104-2221-E-468-007。
文摘The number of films is numerous and the film contents are complex over the Internet and multimedia sources. It is time consuming for a viewer to select a favorite film. This paper presents an automatic recognition system of film types. Initially, a film is firstly sampled as frame sequences. The color space, including hue, saturation,and brightness value(HSV), is analyzed for each sampled frame by computing the deviation and mean of HSV for each film. These features are utilized as inputs to a deep-learning neural network(DNN) for the recognition of film types. One hundred films are utilized to train and validate the model parameters of DNN. In the testing phase, a film is recognized as one of the five categories, including action, comedy, horror thriller, romance, and science fiction, by the trained DNN. The experimental results reveal that the film types can be effectively recognized by the proposed approach, enabling the viewer to select an interesting film accurately and quickly.
基金the National Natural Science Foundation of China(Grant Nos.62071221 and 62071442)the Equipment Advance Research Foundation of China(Grant No.80909010302)the Key Laboratory of Radar Imaging and Microwave Photonics(Nanjing University of Aeronautics and Astronautics),Ministry of Education of China(Grant No.NJ20210006).
文摘A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size,the considerable advantages in much lower asymptotic frequency with tight field confinement,which enable the proposed filter to be more miniaturization.A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths.The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric,while the high-frequency cutoff band is realized by the proposed SSPPs structure.The influence of dispersion relation,electric field distribution,surface current,and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain(FDTD).To validate the design concept,the prototype of the miniaturized SSPPs BPF has been manufactured and measured.The experimental results show high performance of the fabricated sample,in which the working in a range of 0.9 GHz-5.2 GHz with the relative bandwidth is 142%,the insertion loss less than 0.5 dB,the reflection coefficient less than-10 dB,and the group delay is less than one ns.This works provides a mirror for realizing the miniaturization of waveguides,and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U2141232,62071221,and 62071442)the Aeronautical Science Foundation of China(Grant No.2019ZA037001)。
文摘An ultra-wideband bandpass filter(BPF)with a wide out-of-band rejection based on a surface plasmonic waveguide(SPW)slotline with ring grooves is designed and analyzed.A paired microstrip-to-slotline transition is designed for quasiTEM to TM mode conversion by using a microstrip line with a circular pad and the slotline with the same circular slot.The mode conversion between the TM and the surface plasmon polariton(SPP)mode is realized by using a gradient slotline with ring grooves and an impedance matching technique.The upper cut-off frequencies of the passband can be adjusted by using these proposed SPP units,while the lower frequencies of the passband are created by using the microstrip-toslotline transitions to give an ultra-wideband BPF.The dispersion curves of SPP units,electric field distribution,and the transmission spectra of the proposed ultra-wideband bandpass filter are all calculated and analyzed by the finite-difference time-domain(FDTD)method.The simulated results show that the presented filter has good performance including a wide3-dB bandwidth of 149%from 0.57 GHz to 3.93 GHz,an extremely wide 40-dB upper-band rejection from 4.2 GHz to18.5 GHz,and low loss and high selectivity in the passband.To prove the design validity,a prototype of the BPF has been manufactured and measured,showing a reasonable agreement with simulation results.The unique features of the proposed BPF may make it applicable for integrated circuit and plasmonic devices in microwave or THz frequency ranges.
基金supported by the National Natural Science Foundation of China (Grant No. 51179058)National Science Fund for Distinguished Young Scholars (Grants No. 51125034 and 50925932)+1 种基金the Special Fund for Public Welfare of the Water Resources Ministry of China (Grant No. 201201017)the 111 Project (Grant No. B12032)
文摘Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes (N-S) equations were numerically solved with the fractional-step method in sigma coordinates. The subgrid-scale turbulent stress was modeled with a dynamic coherent eddy viscosity model proposed by the authors The computed velocity profiles are in good agreement with the available experimental results. The mean velocity and the turbulent Reynolds stress affected by a series of dune-shaped structures were compared and analyzed. The variation of turbulence statistics along the flow direction affected by the wavy bottom roughness has been studied. The turbulent boundary layer in a complex geographic environment can be simulated well with the proposed large eddy simulation (LES) model.
基金supported by MOST under Grant No.104-2221-E-468-007
文摘Images are generally corrupted by impulse noise during acquisition and transmission.Noise deteriorates the quality of images.To remove corruption noise,we propose a hybrid approach to restoring a random noisecorrupted image,including a block matching 3D(BM3D)method,an adaptive non-local mean(ANLM)scheme,and the K-singular value decomposition(K-SVD)algorithm.In the proposed method,we employ the morphological component analysis(MCA)to decompose an image into the texture,structure,and edge parts.Then,the BM3D method,ANLM scheme,and K-SVD algorithm are utilized to eliminate noise in the texture,structure,and edge parts of the image,respectively.Experimental results show that the proposed approach can effectively remove interference random noise in different parts;meanwhile,the deteriorated image is able to be reconstructed well.
基金Supported by National Natural Science Foundation of China(General Program)No.81670815+1 种基金Guangdong Basic and Applied Basic Research Foundation,No.2020A1515010124,No.2021A1515010695Special Fund for Innovation Strategy of Science and Technology plan of Guangdong Province,No.2019A030317011。
文摘BACKGROUND Previous studies have shown that diabetes mellitus is a common comorbidity of coronavirus disease 2019(COVID-19),but the effects of diabetes or anti-diabetic medication on the mortality of COVID-19 have not been well described.AIM To investigate the outcome of different statuses(with or without comorbidity)and anti-diabetic medication use before admission of diabetic after COVID-19.METHODS In this multicenter and retrospective study,we enrolled 1422 consecutive hospitalized patients from January 21,2020,to March 25,2020,at six hospitals in Hubei Province,China.The primary endpoint was in-hospital mortality.Epidemiological material,demographic information,clinical data,laboratory parameters,radiographic characteristics,treatment and outcome were extracted from electronic medical records using a standardized data collection form.Most of the laboratory data except fasting plasma glucose(FPG)were obtained in first hospitalization,and FPG was collected in the next day morning.Major clinical symptoms,vital signs at admission and comorbidities were collected.The treatment data included not only COVID-19 but also diabetes mellitus.The duration from the onset of symptoms to admission,illness severity,intensive care unit(ICU)admission,and length of hospital stay were also recorded.All data were checked by a team of sophisticated physicians.RESULTS Patients with diabetes were 10 years older than non-diabetic patients[(39-64)vs(56-70),P<0.001]and had a higher prevalence of comorbidities such as hypertension(55.5%vs 21.4%,P<0.001),coronary heart disease(CHD)(9.9%vs 3.5%,P<0.001),cerebrovascular disease(CVD)(3%vs 2.2%,P<0.001),and chronic kidney disease(CKD)(4.7%vs 1.5%,P=0.007).Mortality(13.6%vs 7.2%,P=0.003)was more prevalent among the diabetes group.Further analysis revealed that patients with diabetes who took acarbose had a lower mortality rate(2.2%vs 26.1,P<0.01).Multivariable Cox regression showed that male sex[hazard ratio(HR)2.59(1.68-3.99),P<0.001],hypertension[HR 1.75(1.18-2.60),P=0.006),CKD[HR 4.55(2.52-8.20),P<0.001],CVD[HR 2.35(1.27-4.33),P=0.006],and age were risk factors for the COVID-19 mortality.Higher HRs were noted in those aged≥65(HR 11.8[4.6-30.2],P<0.001)vs 50-64 years(HR 5.86[2.27-15.12],P<0.001).The survival curve revealed that,compared with the diabetes only group,the mortality was increased in the diabetes with comorbidities group(P=0.009)but was not significantly different from the noncomorbidity group(P=0.59).CONCLUSION Patients with diabetes had worse outcomes when suffering from COVID-19;however,the outcome was not associated with diabetes itself but with comorbidities.Furthermore,acarbose could reduce the mortality in diabetic.
基金supported by the National Natural Science Foundation of China(no.31971497)the Xingdian Scholar Fund of Yunnan and by Double Top University Fund of Yunnan University。
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3202605)supported by the Water Conservancy Science and Technology Project in Jiangsu Province(Grant No.2022061)the 111 Project(Grant No.B17015).
文摘This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder.A mathematical model of numerical wave tank with two-way fluid-solid interactions were developed and validated.The wave-induced vibrations of a single-degree-of-freedom cylinder were simulated at eleven gap ratios(d/a=8,10,12,14,16,18,20,22,24,28 and 32).Numerical results indicate that significant nonlinear characteristics are introduced into the originally linear waves with the presence of cylinder.Based on the variation characteristics of cylinder vibration amplitude,the gap ratios can be divided into three ranges,i.e.,the uncertain range(8≤d/a≤14),quasi-linear range(14≤d/a≤20)and linear range(20≤d/a≤32).Under the same wave condition,the gap ratio does not affect the frequencies of vortex shedding and cylinder vibration.The presence of the cylinder complicates the flow field and suppress the vortex shedding around the cylinder.
基金National Natural Science Foundation of China(NSFC)(11574079,61505052,61775055)
文摘Near-field coupled plasmonic systems generally achieve plasmonically induced transparency(PIT) using only one-way bright–dark mode coupling. However, it is challenging to realize such well-designed devices,mainly because they depend significantly on the polarization direction. We exploit surface plasmons supported by two crossed layers of graphene nanoribbons(GNRs) to achieve dynamically tunable PIT, where each GNR operates as both the bright and dark modes simultaneously. The proposed PIT can result from either one-way bright–dark mode interactions or bidirectional bright–bright and bright–dark mode hybridized coupling when the polarization is perpendicular/parallel or at an angle to the GNRs, respectively.Additionally, identical ribbon widths yield polarization-insensitive single-window PIT, whereas different ribbon widths produce polarization-dependent double-window PIT. We examine the proposed technique using plasmon wave functions and the transfer matrix method; analytical and numerical results show excellent agreement. This study can provide physical insight into the PIT coupling mechanisms and advance the applicability and versatility of PIT-based sensing platforms and other active devices.