Early peripheral perfusion index predicts 28-day outcome in patients with septic shock

BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic shock.METHODS:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August 2023.These patients were divided into survival(n=84)and death(n=116)groups based on 28-day outcomes.Clinical evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after admission.Risk factors associated with mortality were analyzed using univariate and multivariate Cox regression analyses.Receiver operator characteristic(ROC)curve was used to assess predictive performance.Mortality rates were compared,and Kaplan-Meier survival plots were created.RESULTS:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid replacement.Higher lactate levels and lower PPI levels at 0 h,6 h,and 12 h were observed in the death group.Multivariate Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 12-h PPI as independent risk factors for death.The area under the curves for 6-h PPI and 12-h PPI were 0.802(95%CI 0.742-0.863,P<0.001)and 0.945(95%CI 0.915-0.974,P<0.001),respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 12 h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;12-h PPI:92.04%vs.13.79%,P<0.001).CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock.

Psychometric properties of the Chinese Version of the Readiness for Hospital Discharge Scale for people living with HIV

Objective:The study was conducted to validate the reliability and factor structure of the Chinese version of the Readiness for Hospital Discharge Scale(RHDS-CH)for people living with HIV(PLWH).Methods:From May 2017 to November 2017,a cross-sectional survey was performed in two AIDS inpatient departments located in two cities in Hunan,China.Reliability was evaluated by examining the internal consistency and split-half reliability of the items.A confirmatory factor analysis was performed to assess the factor structure of the RHDS-CH,and the model was revised according to the modification index.Results:Cronbach'sαfor the RHDS-CH was 0.912,and the split-half reliability of the total scale was 0.831.Initially,the results of the confirmatory factor analysis indicated that the sample did not fit this four-factor model and its 23 items well(x2/df=3,GFI=0.772,TLI=0.823,CFI=0.844,RMSEA=0.100).To improve the model fit indices,we performed model modification with the guidance of modification indices.Finally,the model fit indices showed an acceptable fit to the data(x2/df=2.141,GFI=0.844,TLI=0.899,CFI=0.915,RMSEA=0.075).Coefficients of corrected item-total correlation of the RHDS-CH ranged from 0.435 to 0.726.Conclusion:This study is the first to examine the psychometric properties of the RHDS-CH for PLWH.Our findings showed good reliability and confirmed the four-factor structure model for PLWH.

Astrocytic effect of low molecular weight heparin-superoxide dismutase conjugate in interleukin-6 overexpressing mice following local cerebral ischemia

BACKGROUND： Studies have shown that low molecular weight heparin-superoxide dismutase conjugate exhibits a remarkable neuroprotective effect. OBJECTIVE： To investigate the effect of low molecular weight heparin-superoxide dismutase conjugate on astrocytes in an interleukin-6 （IL-6） overexpressing mice following local cerebral ischemia. DESIGN, TIME AND SETTING： Randomized, cytological, controlled, animal study was performed in the Department of Physiology and Neuroscience, Neurology and Biochemistry and Molecular Biology, Medical University of South Carolina from January 2005 to March 2005. MATERIALS： Nine IL-6 transgenic mice, irrespective of gender, were randomly divided into three groups： sham-operated, model, and treatment, with three mice in each group. With exception of the sham-operated group, right middle cerebral artery occlusion was induced in the mice. Expression of glial fibrillary acidic protein, an astrocyte marker, was determined by immunohistochemistry. Low molecular weight heparin-superoxide dismutase conjugate was purchased from Biochemistry and Biotechnique Institute, Shandong University. METHODS： Two minutes prior to ischemia induction, 0.5 mL/kg saline or 20 000 U/kg low molecular weight heparin-superoxide dismutase conjugate were administrated via the femoral artery in the model group and treatment group, respectively. The sham-operated group underwent the same protocols, with the exception of occlusion and treatment. MAIN OUTCOME MEASURES： The number of glial fibrillary acidic protein-positive cells was quantified under light microscopy （x200）. RESULTS： In the sham-operated group, there were a large number of astrocytes in the IL-6 transgenic mice. However, the cell bodies were small, and the branches were few and thin. The number of astrocytes in the model group was remarkably less than the sham-operated group. Compared to the model and sham-operated groups, the number of astrocytes significantly increased, and the cell body became larger, following treatment with low molecular weight heparin-superoxide dismutase conjugate. Astrocytes exhibited hypertrophy and hyperplasia, and the processes became longer and thicker. CONCLUSION： The low molecular weight heparin-superoxide dismutase conjugate may provide neuroprotection through astrocytic activation at the super-early stage of cerebral ischemia and reperfusion.

Should we continue breastfeeding after SARS-CoV-2 infection or mRNA vaccination?

The coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has posed a potential threat to infant health.The World Health Organization recommended that the benefits of breastfeeding far outweigh the potential risk of transmission,but there is no denying that the current evidence is insufficient.Moreover,although the COVID-19 mRNA vaccine has played an effective role in protection against infection,individuals have increasing concerns about the safety of breastfeeding after vaccination,and which have caused some breastfeeding women to postpone vaccination or stop breastfeeding early.Thus,in this review,we provide an in-depth discussion of whether SARS-CoV-2 and the vaccine will affect babies through breast milk.On one hand,only a very small number of milk samples were identified positive for viral RNA and almost impossible to be live virus particles.The milk of most lactating women after vaccination did not contain vaccine-related mRNA and polyethylene glycol.On the other hand,the antibodies and biologically active molecules like lactoferrin are abundant in the milk of lactating women who have been infected or vaccinated,which can provide potential protection against infants’respiratory and gastrointestinal infections.Therefore,in terms of implications for clinical practice,the results of our study support that lactating women who have been infected or vaccinated should be encouraged to breastfeed their infants under the premise of taking appropriate sanitary measures.

Discussion on Mode of Key Link in Increase and Decrease Connection of Urban and Rural Construction Land

With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land.

A Preliminary Study on the Breeding of Late-maturing Daylily Cultivar Jinlei No.1

In order to stagger the early harvest stage of daylily and critical busy summer farming season in Qingyang City, late-maturing daylily cultivar Jinlei No. 1 was systematically bred from natural variant offspring of Malian daylily. According to the results, late-maturing daylily eultivar Jinlei No. 1 exhibited good agro- nomic traits and strong resistance, The first day of harvest of Jinlei No. 1 was more than 10 d later compared with Malian daylily and Xian daylily ; harvest duration of Jinlei No. 1 was 4 d longer than Malian daylily and 5 d than Xian daylily; the yield of Jinlei No. 1 was improved by 3.41% and 5.16% compared with Malian daylily and Xian daylily, respectively. The cultivation of late-maturing daylily cuhivar Jinlei No. 1 can effectively avoid heavy economic losses caused by overlap period of early harvest of daylily and critical busy summer farming in Qingyang City.

Environmental Sound Recognition Using Double-Level Energy Detection

The performance of classic Mel-frequency cepstral coefficients (MFCC) is unsatisfactory in noisy environment with different sound sources from nature. In this paper, a classification approach of the ecological environmental sounds using the double-level energy detection (DED) was presented. The DED was used to detect the existence of the sound signals under noise conditions. In addition, MFCC features from the frames which were detected the presence of the sound signals by DED were extracted. Experimental results show that the proposed technology has better noise immunity than classic MFCC, and also outperforms time-domain energy detection (TED) and frequency-domain energy detection (FED) respectively.

Expression and Significance of Regulatory B Cells in Patients with Immune Thrombocytopenia

Objective: To detect the expression and significance of regulatory B cells in patients with immune thrombocytopenia. Methods: 73 ITP patients were divided into glucocorticoids treatment group (n = 42) and recombinant human thrombopoietin (rhTPO) treatment group (n = 31). According to the therapeutic effect, it was divided into effective group and ineffective group. The expression of CD19+ CD24hiCD38hi Breg in peripheral blood was detected by flow cytometry before and after treatment. The expression levels of transforming growth factor (TGF)-β1, interleukin (IL-10) and interferon (IFN)-γ were detected by ELISA before and after treatment. 30 volunteers were selected as the control group. Results: The expression of CD19+ CD24hiCD38hi Breg and cytokines IL-10 and TGF-β1 in 73 ITP patients before treatment was lower than that in the control group, while the expression of IFN-γ was higher than that in the control group (p < 0. 05). The expression levels of CD19+ CD24hiCD38hi Breg, IL-10 and TGF-β1 in the effective group were significantly higher than before treatment, while the expression of IFN-γ was significantly lower than before treatment (p < 0. 05). The expression of CD19+ CD24hiCD38hi Breg, IFN-γ, IL-10 and TGF-β1 in the invalid group had no significant change compared with before treatment. Conclusion: Abnormal expression of CD19+ CD24hiCD38hi Breg and related cytokines is involved in the pathogenesis of ITP.

76-m分辨率火星全球彩色影像数据集

Remote-sensing images of Mars contain rich information about its surface morphology,topography,and geological structure.These data are fundamental for scientific research and exploration.Prior to China’s first Mars exploration mission,data from six advanced optical imaging systems of different missions in the Martian orbit had been used to generate Mars global/near-global image datasets with spatial resolutions of better than 1 km:the visual imaging system of Mariner 9,visual imaging subsystem cameras of Viking 1 and 2,Mars Orbiter Camera-Wide Angle(MOC-WA)of the Mars Global Surveyor(MGS),Context Camera(CTX)of the Mars Reconnaissance Orbiter(MRO),High Resolution Stereo Camera(HRSC)of Mars Express(MEX),and Thermal Emission Imaging System(THEMIS)of the Mars Odyssey Orbiter[1,2].

Multi-functional epoxides cross-linked collagen sponges for tissue engineering scaffolds

With the efficient cross-linking abilities and the flexible regulation abilities to the performances of cross-linked products,the multi-functional aliphatic epoxides were once widely used to cross-link the collagen-based materials in the last century.In present work,the multi-functional epoxides were used to construct and cross-link collagen sponges for tissue engineering scaffolds,which was hoped to board the theoretical system of epoxides and explore their potentials for modern applications.The bi-to tetra-functional epoxides were used to cross-link collagen solutions and establish the gel-like precursors,then using freeze-drying to form the final sponges.The SEM observed that the sponges had shown regular porous structures with a wide range of pore sizes from 160 to 440μm.The sponges had presented the resistance to enzymatic degradation,shape-remaining ability,and reversible compressibility in aqueous environments,which all could be regulated through the functionalities of epoxides.The regulation abilities of multi-functional epoxides on the performances of sponges had been mainly achieved through the cross-linking degrees that the higherfunctionality of epoxides would bring higher cross-linking degree.Such higher cross-linking degrees could enhance the elastic behaviors of gel-like precursors,and improve the compressive strengths and thermal stabilities of sponges.Nevertheless,the multi-functional epoxides had barely affected the safety of collagen sponges at the cellular level according to the results of CCK8 assay and the SEM and CLSM images of L929 fibroblasts cultured on the cross-sections of sponges.

High-strength collagen/delphinidin film incorporated with Vaccinium oxycoccus pigment for active and intelligent food packaging

This study developed an active and intelligent collagen-based packaging film with high strength for visually monitoring the freshness of fish.The results of scanning electron microscopy and atomic force microscopy showed that the film based on cross-linked collagen/delphinidin catalyzed by laccase exhibited a denser layer structure and a rougher surface.The dry and wet tensile strengths of the laccase-catalyzed collagen/delphinidin film(Col/Dp-LA film)increased by 41.74 MPa and 13.13 MPa in comparison with that of the pure collagen film,respectively.Moreover,the Col/Dp-LA film presented good antioxidant and barrier properties demonstrated by the results of free radical scavenging rate,light transmission rate,and water vapor permeability.The intelligent collagen-based film was obtained by incorporating Vaccinium oxycoccus pigment into the Col/Dp-LA film,which could change color under different pH values.When applied to the preservation offish fillets,the film could release Dp to minimize oxidative rancidity and prolong the shelf life of the fish for 2 days.Meanwhile,the film showed visual color changes from purplish-red to greyish-blue after the fish spoilage.These results indicated that the collagen film treated with delphinidin,laccase,and Vaccinium oxycoccus pigment has potential application value in the field of active and intelligent food packaging.

三株固氮类芽孢杆菌的特点及其对中国青菜的产量和土壤酶活性的影响（英文）

【目的】本研究分析三株固氮菌PGPR性状特征及其对中国青菜产量和土壤酶活的影响。【方法】氮(N)-修复(固氮)细菌被认为是一种能够促进植物生长和增产的施氮方式。在本研究中,我们用无氮培养基分离出了30株根际固氮细菌:11株来自小麦根际,16株来自中国青菜根际和3株来自莲花根际。基于16S r DNA序列分析,对小麦、中国青菜和莲花等植物根际中属于类芽孢杆菌属的主要固氮细菌进行研究。【结果】本研究从这30株固氮菌中筛选出三株属于类芽孢杆菌属(Paenibacillus)的细菌,分别命名为P-4、W-7和L-3,它们的固氮酶活性不但高于对照组(圆褐固氮菌),而且可以有效抑制两种或三种植物病原菌的生长,即核盘菌(Sclerotinia sclerotiorum)、玉蜀黍赤霉(Gibberella zeae)和棉花黄萎病菌(Verticillium dahliae)。菌株W-7还具有溶解难溶磷的能力,中国青菜在接种菌株W-7和L-3后,其鲜重显著增加,同时改变了田间土壤蔗糖酶、磷酸酶和过氧化氢酶的活性;而接种了菌株P-4对植物的生长和酶活性没有显著的影响。【结论】土壤蔗糖酶、磷酸酶和过氧化氢酶活性与中国青菜的生物量呈正相关。同时,菌株W-7和L-3具有促进植物产量和提高土壤质量的良好潜力。

Adsorption behaviors of strontium using macroporous silica based hexagonal tungsten oxide

A novel macroporous silica-based hexagonal tungsten oxide （h-WO3/SiO2） with exchangeable sodium cations located in hex- agonal tunnel structure was synthesized by a facile hydrothermal treatment of sodium tungstate dihydrate with 1 mol/L HCl solution. Utilization of the h-WO3/SiO2 adsorbent to remove aqueous strontium was investigated under the condition of various pH values, contact time, the initial concentration of metal ions, salt ion concentration, and coexisting ions. According to the experimental data, Sr2＋ adsorption equilibrium was achieved within 15 min in acidic solution, and the maximum removal ca- pacity of Sr2＋ occurred at pH 4. The kinetic adsorption of Sr2＋ on h-WO3/SiO2 was controlled by pseudo second-order model, and the saturated adsorption of Sr2＋ on h-WO3/SiO2 was better described by Langmuir and Redlich-Peterson isotherm models compared with the Freundlich isotherm model. The distribution coefficient of St2＋ was more than 2000 cm3/g in the presence of Ca2＋, Mg2＋, La3＋, and Eu3＋, indicating that the h-WO3/SiO2 showed excellent selectivity towards Sr2＋ in pH 4.

Visualizing the Transport of Porcine Reproductive and Respiratory Syndrome Virus in Live Cells by Quantum Dots-Based Single Virus Tracking

Quantum dots(QDs)-based single particle analysis technique enables real-time tracking of the viral infection in live cells with great sensitivity over a long period of time.The porcine reproductive and respiratory syndrome virus(PRRSV)is a small virus with the virion size of 40–60 nm which causes great economic losses to the swine industry worldwide.A clear understanding of the viral infection mechanism is essential for the development of effective antiviral strategies.In this study,we labeled the PRRSV with QDs using the streptavidin–biotin labeling system and monitored the viral infection process in live cells.Our results indicated that the labeling method had negligible effect on viral infectivity.We also observed that prior to the entry,PRRSV vibrated on the plasma membrane,and entered the cells via endosome mediated cell entry pathway.Viruses moved in a slow–fast–slow oscillatory movement pattern and finally accumulated in a perinuclear region of the cell.Our results also showed that once inside the cell,PRRSV moved along the microtubule,microfilament and vimentin cytoskeletal elements.During the transport process,virus particles also made contacts with non-muscle myosin heavy chainⅡ-A(NMHCⅡ-A),visualized as small spheres in cytoplasm.This study can facilitate the application of QDs in virus infection imaging,especially the smaller-sized viruses and provide some novel and important insights into PRRSV infection mechanism.

Factors affecting thermal stability of collagen from the aspects of extraction,processing and modification

Collagen,as a thermal-sensitive protein,is the most abundant structural protein in animals.Native collagen has been widely applied in various fields due to its specific physicochemical and biological properties.The beneficial properties would disappear with the collapse of the unique triple helical structure during heating.Understanding thermal stability of collagen is of great significance for practical applications.Previous studies have shown the thermal stability would be affected by the different sources,extraction methods,solvent systems in vitro and modified methods.Accordingly,the factors affecting thermal stability of collagen are discussed in detail in this review.

On the mean radiative efficiency of accreting massive black holes in AGNs and QSOs

Radiative efficiency is an important physical parameter that describes the fraction of accretion material converted to radiative energy for accretion onto massive black holes （MBHs）. With the simplest Sottan argument, the radiative efficiency of MBHs can be estimated by matching the mass density of MBHs in the local universe to the accreted mass density by MBHs during AGN/QSO phases. In this paper, we estimate the local MBH mass density through a combination of various determinations of the correlations between the masses of MBHs and the properties of MBH host galaxies, with the distribution functions of those galaxy properties. We also estimate the total energy density radiated by AGNs and QSOs by using various AGN/QSO X-ray luminosity functions in the literature. We then obtain several hundred estimates of the mean radiative efficiency of AGNs/QSOs. Under the assumption that those estimates are independent of each other and free of systematic effects, we apply the median statistics as described by Gott et al. and find the mean radiative efficiency of AGNs/QSOs is ε = 0.105＋0.006- 0.008, which is consistent with the canonical value -0.1. Considering that about 20% Compton-thick objects may be missed from current available X-ray surveys, the true mean radiative efficiency may be actually -0.12.