Prevention and Control Strategies of Nosocomial Infection and Effectiveness Evaluation in a Tertiary Teaching Hospital during the Epidemic of COVID-19

Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital initiated an emergency plan involving multi-departmental defense and control. It adopted a series of nosocomial infection prevention and control measures, including strengthening pre-examination and triage, optimizing the consultation process, improving the hospital’s architectural composition, implementing graded risk management, enhancing personal protection, and implementing staff training and supervision. Descriptive research was used to evaluate the short-term effects of these in-hospital prevention and control strategies. The analysis compared changes in related evaluation indicators between January 24, 2020 and February 12, 2020 (Chinese Lunar New Year’s Eve 2020 to lunar January 19) and the corresponding lunar period of the previous year. Results: Compared to the same period last year, the outpatient fever rate increased by 1.85-fold (P P Conclusion: The nosocomial infection prevention and control strategies implemented during this specific period improved the detection and control abilities for the COVID-19 source of infection and enhanced the compliance with measures. This likely contributed significantly to avoiding the occurrence of nosocomial infection.

Factors affecting mito-nuclear codon usage interactions in the OXPHOS system of Drosophila melanogaster

Codon usage bias varies considerably among genomes and even within the genes of the same genome. In eukaryotic organisms, energy production in the form of oxidative phosphorylation （OXPHOS） is the only process under control of both nuclear and mitochondrial genomes. Although factors affecting codon usage in a single genome have been studied, this has not occurred when both interactional genomes are involved. Consequently, we investigated whether or not other factors influence codon usage of coevolved genes. We used Drosophila melanogaster as a model organism. Our χ^2 test on the number of codons of nuclear and mitochondrial genes involved in the OXPHOS system was significantly different （χ^2= 7945.16, P 〈 0.01）. A plot of effective number of codons against GC3s content of nuclear genes showed that few genes lie on the expected curve, indicating that codon usage was random. Correspondence analysis indicated a significant correlation between axis 1 and codon adaptation index （R = 0.947, P 〈 0.01） in every nuclear gene sequence. Thus, codon usage bias of nuclear genes appeared to be affected by translational selection. Correlation between axis 1 coordinates and GC content （R = 0.814, P 〈 0.01） indicated that the codon usage of nuclear genes was also affected by GC composition. Analysis of mitochondrial genes did not reveal a significant correlation between axis 1 and any parameter. Statistical analyses indicated that codon usages of both nDNA and mtDNA were subjected to context-dependent mutations.

Tuning of the Magnetic Damping Parameter by Varying Cr Composition in Fe1-xCrx Alloy

We investigate the magnetic damping parameter of Fe 1−x Cr x thin films using the time-resolved magneto-optical Kerr effect technique.It is demonstrated that the overall effective damping parameter is enhanced with the increasing Cr concentration.The effective damping at high fieldα0 is found to be significantly enhanced when increasing the Cr concentration with theα0=0.159 in the Fe 45 Cr 55 enhanced by 562%compared with that ofα0=0.024 in the pure Fe film.This study provides a new approach of controlling the effective damping parameter with a desired magnitude via varying Cr composition.

Visible light-driven oxidation of non-native substrate by laccase attached on Ru-based metal-organic frameworks

Light-induced electron transfer can broaden the substrate range of metalloenzyme.However,the efficiency of photo-enzyme coupling is limited by the poor combination of photosensitizer or photocatalyst with enzyme.Herein,we prepared the nano-photocatalyst MIL-125-NH_(2)@Ru(bpy)by in site embedding ruthenium pyridine-diimine complex[Ru(bpy)_(3)^(2+)into metal organic frameworks MIL-125-NH_(2)and associated it with multicopper oxidase(MCO)laccase.Compared to[Ru(bpy)_(3)]^(2+),the coupling efficiency of MIL-125-NH_(2)@Ru(bpy)_(3)for enzymatic oxygen reduction increased by 35.7%.A series of characterizations confirmed that the amino group of laccase formed chemical bonds with the surface defects or hydrophobic groups of MIL-125-NH_(2)@Ru(bpy)_(3).Consequently,the tight binding accelerated the quenching process and electron transfer between laccase and the immobilized ruthenium pyridine-diimine complex.This work would open an avenue for the synthesis of MOFs photocatalyst towards photo-enzyme coupling.

LonP1 Links Mitochondria–ER Interaction to Regulate Heart Function

Interorganelle contacts and communications are increasingly recognized to play a vital role in cellular function and homeostasis.In particular,the mitochondria–endoplasmic reticulum(ER)membrane contact site(MAM)is known to regulate ion and lipid transfer,as well as signaling and organelle dynamics.However,the regulatory mechanisms of MAM formation and their function are still elusive.Here,we identify mitochondrial Lon protease(LonP1),a highly conserved mitochondrial matrix protease,as a new MAM tethering protein.The removal of LonP1 substantially reduces MAM formation and causes mitochondrial fragmentation.Furthermore,deletion of LonP1 in the cardiomyocytes of mouse heart impairs MAM integrity and mitochondrial fusion and activates the unfolded protein response within the ER(UPR^(ER)).Consequently,cardiac-specific LonP1 deficiency causes aberrant metabolic reprogramming and pathological heart remodeling.These findings demonstrate that LonP1 is a novel MAM-localized protein orchestrating MAM integrity,mitochondrial dynamics,and UPR^(ER),offering exciting new insights into the potential therapeutic strategy for heart failure.

聚乙烯醇/牛Ⅰ型胶原支架材料的制备及评价

研究了一种聚乙烯醇(PVA)和胶原(COL)复合支架材料的制备方法。采用氨基硅烷对PVA海绵表面进行了氨基化修饰后,通过戊二醛溶液交联牛Ⅰ型胶原(COL),最后通过赖氨酸溶液封闭,获得一种PVA/COL复合支架材料。采用扫描电镜(SEM)、X光电子能谱仪(XPS)、傅里叶红外光谱(FT-IR)等手段对支架材料的理化性能进行表征,并通过细胞实验对支架材料的生物学性能进行评价。结果表明,经过COL修饰的PVA孔隙率为21.33%,平均孔径为168.68mm且均匀分布,支架材料接触角为20.03°。对支架材料的生物学评价结果表明C3A细胞在复合材料上黏附良好,优于PVA组;CCK-8增殖检测结果表明细胞在复合材料上呈增殖生长趋势,与对照组PVA相比差异显著(P<0.01)。将PVA和COL复合制备得到的支架材料具有良好的理化及生物学特性,具有广阔的应用前景。

A restoration-promoting integrated floating bed and its experimental performance in eutrophication remediation

Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed （RPIFB） was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed （GSB） and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4＋-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration.

Discovery,Identification and Comparative Analysis of Non-Specific Lipid Transfer Protein (nsLtp) Family in Solanaceae

Plant non-specific lipid transfer proteins （nsLtps） have been reported to be involved in plant defense activity against bacterial and fungal pathogens. In this study, we identified 135 （122 putative and 13 previously identified） Solanaceae nsLtps, which are clustered into 8 different groups. By comparing with Boutrot’s nsLtp classification, we classified these eight groups into five types （I, II, IV, IX and X）. We compared Solanaceae nsLtps with Arabidopsis and Gramineae nsLtps and found that （1） Types I, II and IV are shared by Solanaceae, Gramineae and Arabidopsis; （2） Types III, V, VI and VIII are shared by Gramineae and Arabidopsis but not detected in Solanaceae so far; （3） Type VII is only found in Gramineae whereas type IX is present only in Arabidopsis and Solanaceae; （4） Type X is a new type that accounts for 52.59% Solanaceae nsLtps in our data, and has not been reported in any other plant so far. We further built and compared the three-dimensional structures of the eight groups, and found that the major functional diversification within the nsLtp family could be predated to the monocot/dicot divergence, and many gene duplications and sequence variations had happened in the nsLtp family after the monocot/dicot divergence, especially in Solanaceae.

Response of ammonia-oxidizing archaea to heavy metal contamination in freshwater sediment

It has been well-documented that the distribution of ammonia-oxidizing bacteria(AOB) and archaea(AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these ammonia-oxidizing microorganisms in freshwater sediment is still lacking. The present study explored the change of sediment ammonia-oxidizing microorganisms in a freshwater reservoir after being accidentally contaminated by industrial discharge containing high levels of metals. Bacterial amoA gene was found to be below the quantitative PCR detection and was not successfully amplified by conventional PCR. The number of archaeal amoA gene in reservoir sediments were 9.62 × 10~2–1.35 × 10~7 copies per gram dry sediment. AOA abundance continuously decreased, and AOA richness, diversity and community structure also considerably varied with time. Therefore, heavy metal pollution could have a profound impact on freshwater sediment AOA community. This work could expand our knowledge of the effect of heavy metal contamination on nitrification in natural ecosystems.

Positioning taxonomic research for the future

Why do taxonomists matter? The work of taxonomists is often understated if not completely misunderstood. Without taxonomists, organisms cannot be accurately identified, neither can these organisms be given universally accepted names, and reliably positioned in the phylogenetic tree of life. Thanks to the work of taxonomists over the last 269 years since Carl Linnaeus established the binomial system, we can now measure the health and wealth of our biodiversity in a refined, science-based inventory prescribed by stringent nomenclatural rules.

Genomes of 12 fig wasps provide insights into the adaptation of pollinators to fig syconia

Figs and fig pollinators are one of the few classic textbook examples of obligate pollination mutualism.The specific dependence of fig pollinators on the relatively safe living environment with sufficient food sources in the enclosed fig syconia implies that they are vulnerable to habitat changes.However,there is still no extensive genomic evidence to reveal the evolutionary footprint of this long-term mutually beneficial symbiosis in fig pollinators.In fig syconia,there are also non-pollinator species.The non-pollinator species differ in their evolutionary and life histories from pollinators.We conducted comparative analyses on 11 newly sequenced fig wasp genomes and one previously published genome.The pollinators colonized the figs approximately 66.9 million years ago,consistent with the origin of host figs.Compared with nonpollinators,many more genes in pollinators were subject to relaxed selection.Seven genes were absent in pollinators in response to environmental stress and immune activation.Pollinators had more streamlined gene repertoires in the innate immune system,chemosensory toolbox,and detoxification system.Our results provide genomic evidence for the differentiation between pollinators and nonpollinators.The data suggest that owing to the long-term adaptation to the fig,some genes related to functions no longer required are absent in pollinators.