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AIMS: To explore the contagiousness and new SARS-CoV-2 mutations in pediatric COVID-19. METHODS: This cohort study enrolled all pediatric patients admitted to 8 hospitals in Zhejiang Province of China between 21 January and 29 February 2020, their family members and close-contact classmates. Epidemiological, demographic, clinical and laboratory data were collected. Bioinformatics was used to analyze the features of SARS-CoV-2. Individuals were divided into 3 groups by the first-generation case: Groups 1 (unclear), 2 (adult), and 3 (child). The secondary attack rate (SAR) and R0 were compared among the groups. RESULTS: The infection rate among 211 individuals was 64% (135/211). The SAR in Groups 2 and 3 was 71% (73/103) and 3% (1/30), respectively; the median R0 in Groups 2 and 3 was 2 (range: 1-8) and 0 (range: 0-1), respectively. Compared with adult cases, the SAR and R0 of pediatric cases were significantly lower (p

The influenza A (H1N1) pdm09 virus attracted public attention because of its high prevalence. The annual global morbidity and mortality rates of influenza remain high despite the application of influenza vaccines and antiviral drugs, which indicates the urgent need to identify a more effective strategy for controlling and treating A(H1N1) pdm09 influenza infection. To produce a highly effective therapeutic with broad specificity for A(H1N1) pdm09 influenza viruses, we generated 15 murine monoclonal antibodies (mAbs) via hybridoma technology: 11 mAbs demonstrated 20-100% therapeutic protection in a mouse model of A(H1N1) pdm09 infection at a single dose of 10 mg/kg. A humanised bispecific antibody (Bis-Hu11-1) generated based on the mAbs 3D2 and 3D11, combining the specificities of the two mAbs, was also effective in preventing and treating A(H1N1) pdm09 infection in a mouse model. Bis-Hu11-1 demonstrated hemagglutination inhibition (HI) activity against the escape mutants generated by its parental mAbs that resulted in the obvious reduction in the HI activity of the parental mAbs. In summary, we generated a panel of neutralising mAbs against A(H1N1) pdm09 influenza virus. This study presents a promising method for developing neutralising antibodies that potentially target a series of antigenically diverse influenza viruses.

To evaluate the ecological risk of aniline wastewater biodegradation, the aniline wastewater (200 mg/L) was treated in this work under the stress of Cu (II) at 3, 6 and 10 mg/L, respectively. The slight fluctuation of aniline-degrading performance and the significant inhibition of nitrogen removal was caused by the Cu (II) stress at below 6 mg/L. Meanwhile, the tolerance of nitrifying performance to Cu (II) was higher than denitrifying. The collapse of biosystem was caused by the Cu (II) stress at 10 mg/L and the decontamination function was disabled within 8 days. The activity and stability of sludge declined under the increase of Cu (II) content. Microbial diversity results demonstrated that the genera with heavy-metal tolerance represented by Zoogloea and Azospira significantly dominated under the continuously Cu (II) stress. Whereas, the biosystem with these dominant genera did not achieve the comparable aniline and nitrogen removal performance as the control group.

Seasonal influenza viruses are highly contagious, leading to 290,000-650,000 mortalities every year globally. Among the influenza viruses, influenza A virus (H3N2) has attracted much attention due to its high frequency of antigenic variations, resulting in poor protection by vaccination. We generated a panel of murine neutralizing monoclonal antibodies (mAbs) against A/Texas/50/2012 (H3N2) and identified the relevant epitopes that potentially influence the antigenicity by selecting mAb-resistant mutants. The epitopes were mainly in antigenic site A (1/9, 11.1%), B (6/9, 66.7%), and C (1/9, 11.1%), which is consistent with recent reports on the immunodominance of antigenic site B. The amino acid substitutions at positions 156, 157, 159, 160, and 189 at antigenic site B resulted in decreased mAb capability for blocking receptor binding. In addition, the neutralizing spectra of three mAbs (1F8, 1G9 and 1H5) were different, suggesting that their epitopes may be different but partially overlapping, and it required further study. Further, the mAb 3F9 selected a new substitution, D53G/N, at antigenic site C and showed in vitro neutralizing activity against A/Victoria/361/2011 (H3N2), A/Texas/50/2012 (H3N2), and A/Hong Kong/2671/2019 (H3N2), suggesting a potential epitope on H3 hemagglutinin for inducing broad neutralizing antibody responses. Continuous research and regular monitoring of novel epitopes are of great importance for improving vaccine strain selection.

An inflammatory, cytokine-rich tumor microenvironment is a defining feature of pancreatic ductal adenocarcinoma (PDAC). Among proinflammatory cytokines, type I interferons (IFNs) are particularly important as they regulate the expression of hundreds of genes. It is however unclear whether IFN signaling in PDAC tumors can be leveraged therapeutically. We determined that a type I IFN response transcriptional signature is enriched in a subset of PDAC and that IFN signaling biomarkers are detectable in patient-derived and cell line xenograft tumors. To systematically identify actionable vulnerabilities induced by IFN, we integrated a mass spectrometry-based phosphoproteomic analysis and a chemical genomics high-throughput synthetic lethality screen which together revealed that IFN activates the replication stress response kinase ataxia telangiectasia and Rad3-related protein (ATR) and sensitizes tumor cells to ATR inhibitors. In vitro, IFNs induce replication stress and cell cycle arrest in S-phase which is accompanied by nucleotide pool insufficiency and enhanced nucleoside efflux into the extracellular environment. In combination with IFN, ATR inhibitors induce lethal DNA damage, downregulate de novo nucleotide biosynthesis mediated by ribonucleotide reductase, and deplete nucleotide pools. In vivo, ATR inhibitors limit the growth of subcutaneous and orthotopic PDAC tumors in which IFN production is driven by the activation of stimulator of interferon genes (STING). These results highlight critical crosstalk between IFN signaling, the DNA replication stress response network, and nucleotide metabolism in PDAC while providing the rationale for exploring targeted therapeutic interventions that leverage the tumor cell autonomous effects of IFN signaling.

The sudden outbreak of the severe acute respiratory syndrome–coronavirus (SARS-CoV-2) has spread globally with more than 1,300,000 patients diagnosed and a death toll of 70,000. Current genomic survey data suggest that single nucleotide variants (SNVs) are abundant. However, no mutation has been directly linked with functional changes in viral pathogenicity. We report functional characterizations of 11 patient-derived viral isolates. We observed diverse mutations in these viral isolates, including 6 different mutations in the spike glycoprotein (S protein), and 2 of which are different SNVs that led to the same missense mutation. Importantly, these viral isolates show significant variation in cytopathic effects and viral load, up to 270-fold differences, when infecting Vero-E6 cells. Therefore, we provide direct evidence that the SARS-CoV-2 has acquired mutations capable of substantially changing its pathogenicity. Funding: This work was supported by funds from Major Project of Zhejiang Provincial Science and Technology Department #2020C03123, National Science and Technology Major Project for the Control and Prevention of Major Infectious Diseases in China (2018ZX10711001, 2018ZX10102001, 2018ZX10302206), and start-606 up funds from Life Sciences Institute at Zhejiang University. Conflict of Interest: None. Ethical Approval: The study was approved by the Clinical Research Ethics Committee of The First Affiliated Hospital, School of Medicine, Zhejiang University (Approval notice 2020-29) for emerging infectious diseases.

In recent years, H5 and H7 subtypes of highly pathogenic avian influenza viruses (HPAIVs) have been identified in poultry worldwide, resulting in large economic losses to poultry production. Furthermore, H9N2 low pathogenic AIVs are reported to provide internal genes for generating novel reassortant AIVs, leading to potential pandemic risks. To establish an accurate, sensitive and convenient diagnostic method for H5, H7 and H9 subtype AIVs in Eurasian lineage, four groups of specific primers and probes were designed based on the conserved fragments of M, H5, H7 and H9 genes, and a multiplex real-time RT-PCR (RRT-PCR) method was established. High sensitivity was achieved for the multiplex RRT-PCR approach, with a detection limit of 1-10 copies (plasmid DNA) per reaction. The specificity of the method was evaluated using diverse subtypes of AIVs and other avian respiratory viruses isolated in eastern China over the last 9 years. Compared with virus isolation, a higher consistency was achieved when assessing 135 field samples and 126 clinical samples. The results showed that the multiplex RRT-PCR method is a fast, convenient and practical method for AIV clinical detection and epidemiological analysis.

High precision sulfur isotope data on eight eucrites and two diogenites are reported to explore the provenance of sulfur and processes that affected the sulfur isotope composition and sulfur abundance within the HED ( H owardite, E ucrite, D iogenite) parent body (Asteroid 4 Vesta) or parent bodies for eucrite-like meteorites. Sulfur isotope values for a subset of six of the eucrites (EET 90020, PCA 82502, BTN 00300, MIL 11290, QUE 97014, and Sioux County) and two diogenites (Johnstown and Shalka) converge on a singular sulfur isotope composition, yielding a mean δ34S of 0.26 ± 0.17‰ (2 SD), Δ33S of 0.010 ± 0.007‰ (2 SD), and Δ36S of −0.22 ± 0.21‰ (2 SD). The variances on these mean values can be entirely accounted for by analytical uncertainties. The homogenous positive Δ33S for these samples suggests that sulfur in Asteroid 4 Vesta has a Δ33S of 0.010 ± 0.002‰ (2 SE) which is consistent with the occurrence of a process that allowed for promoted-isotopic-exchange within the parent body to homogenize Δ33S. This process was previously recognized in the homogenous Δ17O composition that has been linked to large-scale silicate melting and mixing. The positive δ34S of this group of samples is attributed to fractionations associated with sulfur loss, and the homogeneity of sulfur isotopes suggests that this loss predates the mixing event. The sulfur isotope data alone do not differentiate whether this loss occurred prior to or post core formation, or even prior to accretion. Two eucrites (GRA 98098 and CMS 04049) yield isotopic compositions that are distinct from this mean for δ34S, and in the case of CMS 04049, for Δ33S as well. GRA 98098 yields δ34S of 0.81 ± 0.18‰ (2 σest, estimated external precision), Δ33S of 0.010 ± 0.008‰ (2 σest) and Δ36S of 0.01 ± 0.34‰ (2 σest). CMS 04049 yields δ34S of −0.22 ± 0.18‰ (2 σest), Δ33S of 0.024 ± 0.008‰ (2 σest), and Δ36S of −0.17 ± 0.34‰ (2 σest). The more positive δ34S of GRA98098 suggests fractionation of sulfur (34S/32S) by a combination of parent body processes that may be linked to evaporation. The more positive Δ33S and the negative δ34S of CMS 04049 suggests that this meteorite may be from another ‘Vesta-like’ parent body.

H9N2 avian influenza viruses (AIVs) can cause respiratory symptoms and decrease the egg production. Additionally, H9N2 AIVs can provide internal genes for reassortment with other subtypes. During the monitoring of live poultry markets in 2016, a total of 32 (32/179, 17.88%) H9N2 AIVs were isolated from poultry in Eastern China, and seven representative strains were selected based on the isolation time, isolation location and sequence homology for further characterization. Phylogenetic analysis of hemagglutinin and neuraminidase showed that these H9N2 AIVs clustered into the Y280 sublineage. And the phylogenetic trees of six internal genes showed that the source of these gene fragments was more abundant, suggesting that extensive reassortment has occurred in these H9N2 viruses. Molecular analysis showed that multiple specific amino acid mutations occurred that increased H9N2 AIVs' infectivity, transmissibility, and affinity to mammals, including Q226L and Q227M in hemagglutinin, E627K in polymerase basic protein 2 (PB2), L13P in polymerase basic protein 1 (PB1), and A70V and S409N in polymerase acidic protein (PA). Pathogenicity tests in mice showed these H9N2 AIVs could replicate in lungs and exhibited slight to moderate virulence. The continuous circulation of these H9N2 viruses suggests the necessity for persistent surveillance of the H9N2 AIVs in poultry.

Sulfur has multiple stable isotopes (32S, 33S, 34S, and 36S), but little research has been conducted to investigate the information that low abundance sulfur isotope ratios (i.e., 33S/32S and 36S/32S) may carry on ore-forming processes in post-Archean deposits. In this study, the Cretaceous Mina Justa iron oxide–copper–gold deposit, was selected to examine the capability of multiple sulfur isotopes to trace ore-forming processes in post-Archean mineral deposits. In situ secondary ion mass spectrometry was applied to the pyrite of the magnetite–pyrite stage in the deposit to characterize the spatial variation of multiple sulfur isotopes at the microscale. This revealed a clear co-variation trend between δ34S (= 1000 × [(34S/32S)sample/(34S/32S)V-CDT − 1]) and Δ33S (= δ33S − 1000 × [(1 + δ34S/1000)0.515 – 1]). Simple modeling suggests that the triple sulfur isotope data recorded is best explained by mixing magmatic and externally derived (e.g., basinal brine) fluids. The contribution of external fluids is also supported by the trace element distribution patterns in pyrite, as revealed by laser ablation-inductively coupled plasma-mass spectrometry. This study is the first attempt to use multiple sulfur isotopes to trace ore-forming processes in post-Archean deposits and demonstrates that multiple sulfur isotopes are a faithful recorder of ore-forming processes at the microscale, especially when multiple fluids mix.

The H7N9 influenza virus caused significant mortality and morbidity in humans during an outbreak in China in 2013. A recombinant H7N9 influenza seed with hemagglutinin (HA) and neuraminidase (NA) gene segments from A/Zhejiang/DTID-ZJU01/2013(H7N9) and six internal protein gene segments from A/Puerto Rico/8/34(H1N1; PR8) were generated using reverse genetics. We sought to determine the immunogenic, protective properties, and mechanisms of a split avian influenza A/H7N9 vaccine mixed with MF59 adjuvant in comparison to vaccines that included other adjuvant. BALB/c mice were vaccinated with two doses of different amounts and combinations of this novel A/ZJU01/PR8/2013 split vaccine with adjuvant. Mice were subsequently challenged with A/Zhejiang/DTID-ZJU01/2013(H7N9) by intranasal inoculation. We verified that MF59 enhanced the HI, MN, and IgG antibody titers to influenza antigens. Compared with alum, MF59 could more potentially induce humoral immune responses and Th2 cytokine production after virus infection, while both MF59 and alum can slightly increase NK cell activity. This split H7N9 influenza vaccine with MF59 adjuvant could effectively induce antibody production and protect mice from H7N9 virus challenge. We have selected this vaccine for manufacture and future clinical studies to protect humans from H7N9 virus infection.

During the surveillance for avian influenza viruses (AIVs) in live poultry markets in Eastern China, in 2014, seven H6N2 AIVs were isolated from poultry. Phylogenetic analysis showed that these strains received their genes from H6, H3, and H9 AIVs of poultry in China. These strains were found to demonstrate moderate pathogenicity in mice, and were able to replicate in mice without prior adaptation. Considering that novel reassorted H6N2 viruses were isolated from poultry in this study, it is possible that these chickens and ducks play an important role in the generation of novel reassorted H6N2 AIVs.

Microbially-derived nitrogen (N) has been considered as one of important contributors to soil organic N, but few studies have quantified the rate of necromass N decomposition. Here, via an in situ incubation of 15N-labeled necromass, we found that 33.1–39.5% of the initial 15N stabilized in the soil as non-living organic N after 803 days of incubation. Bacterial, fungal, and actinobacterial necromass N showed similar decomposition pattern and mean residence time. The decomposition of microbial necromass N was best simulated by a two-pool model where a labile pool decomposed rapidly (0.4 years), and a more recalcitrant pool decomposed at a much slower rate. This finding contrasted with the decomposition of plant litter N, which was better simulated by a single-pool model. The stabilization of necromass N in soils after more than two years suggests the important contribution of microbial residues to soil organic N, which is most likely due to mineral protection from decomposition.

Objective Chronic activation of the innate immune system plays a central role in HIV-1 disease progression. Negative regulation of innate immunity is critical in preventing the effects of this excessive activation; however, the molecules involved in this process remain to be identified. In this study, we compared the expression of immune regulation genes between HIV-1 infected individuals and healthy control participants to identify genes involved in the regulation of innate immunity in HIV-1 infection. Methods We conducted gene expression analysis of a series of immune regulatory genes in viremic treatment-naive HIV-positive donors, patients receiving highly active antiretroviral therapy (HAART) and HIV-negative healthy control participants. Reverse transcription-quantitative PCR (RT-qPCR) was conducted to determine the expression levels of genes in peripheral blood mononuclear cells isolated from all participants. The spearman correlation test and linear regression analysis were performed to evaluate the correlation between gene expression level and viral load. Results The following differentially expressed genes were identified: A20, CYLD, DDX24, MARCH5, MKRN2, PTP1B, RNF125, S1PR1, SOCS1, IFI35, RBCK1, TTLL12 and USP18. The three most differentially expressed genes were A20, S1PR1, and USP18. USP18 correlated positively with viral load. Conclusion Thirteen immune regulation genes were identified in comparisons of viremic treatment-naive HIV-positive donors, HAART-treated patients and healthy control participants, indicating the potential of these genes as therapeutic targets.

The Ediacaran Period (635–541 Ma) was a time of dramatic environmental and ecological change. Sulfur isotopic records preserved in marine strata provide insights into these changes. Previous work using δ 34 S in pyrite and carbonate-associated sulfate in the Ediacaran-aged Huqf Supergroup (Sultanate of Oman) suggested increases in marine sulfate concentrations, changing microbial pathways and redox conditions, and a long-term increase in δ 34 S of sulfate delivery to the ocean. However, δ 34 S-based analyses on their own were insufficient to uniquely reconstruct these environmental and ecological changes. Here we present new paired δ 34 S and Δ 33 S data from carbonate-associated sulfate and pyrite in these strata. The results allow us to provide three new constraints on Ediacaran sulfur cycling. First, a notable increase Δ 34 S CAS-PY , previously attributed to possible disproportionation, in upper Buah strata is associated with Δ 33 S-evidence for an increase in sulfide reoxidation, indicating a transition to more oxidizing conditions, possibly associated with the onset of bioturbation. Secondly, Δ 33 S data indicate that a large positive shift in both sulfate and pyrite δ 34 S in Ara Group strata is mostly likely due to an increase in delivery of 34 S-enriched sulfate to the basin. Finally paired δ 34 S–Δ 33 S data constrain possible changes in seawater sulfate concentrations, suggesting an increase in sulfate supply related to enhanced evaporite weathering, consistent with geological and geochemical observations that imply high [SO 4 ] (∼17 mM) during deposition of the Ara Group.

Background Since 2004, the H10N7 subtype avian influenza virus (AIV) has caused sporadic human infections with variable clinical symptoms world-wide. However, there is limited information pertaining to the molecular characteristics of H10N7 AIVs in China. Objective To more fully characterize the genetic relationships between three novel H10N7 strains isolated from chickens in Eastern China and the strains isolated from birds throughout Asia, and to determine the pathogenicity of the H10N7 isolates in vivo . Study design All eight gene segments from the Chinese H10N7 strains were sequenced and compared with AIV strains available in GenBank. The virulence of the three isolates was determined in chickens and mice. Results Three H10N7 subtype avian influenza viruses were isolated from chickens in live poultry markets in Eastern China in 2014: (1) A/chicken/Zhejiang/2C66/2014(H10N7) (ZJ-2C66), (2) A/chicken/Zhejiang/2CP2/2014(H10N7) (ZJ-2CP2), and (3) A/chicken/Zhejiang/2CP8/2014(H10N7) (ZJ-2CP8). Phylogenetic analysis indicated that the viruses contained genetic material from H10, H2, H7, and H3 AIV strains that were circulating at the same time. The reassortant H10N7 viruses were found to be minimally pathogenic in chickens and moderately pathogenic in mice. The viruses were able to replicate in mice without prior adaptation. Conclusion These results suggest that H10N7 surveillance in poultry should be used as an early warning system for avian influenza outbreaks. The novel strains identified here may post a threat to human health in the future if they continue to circulate.

During the surveillance for avian influenza viruses (AIVs) in live poultry markets (LPMs) in Eastern China, in 2013, an H10N2 AIV was isolated from a domestic duck. Phylogenetic analysis showed that this strain received its genes from H10, H1 and H7 AIVs of wild birds in China. The virulence of this strain was examined in chickens and mice, and was found to be low pathogenic in chickens but demonstrated moderate pathogenicity in mice. These results suggest that active surveillance of AIVs in LPMs should be used in an early warning system for avian influenza outbreaks.

This study updates the δ34S and Δ33S temporal records of Paleozoic and early Mesozoic seawater sulfate using analysis of carbonate associated sulfate of biogenic and whole rock carbonate. The time resolution of carbonate samples studied here is on the order of millions of years which is longer than the timescale for homogenization of seawater sulfate–sulfur (one tenth of a million years), but is comparable to the timescale for isotope evolution of sulfate in the oceans. This δ34S record confirms the long-term decreasing trend that is discernible over the 250 million year timescale of sampling, and the Δ33S record of seawater sulfate for the Paleozoic is consistent with an average value of − 0.002 ± 0.004 ‰ (2σ, 540–251 Ma) that is distinct from the positive Δ33S observed today and inferred for the rest of the Cenozoic. Both δ34S and Δ33S records of seawater sulfate suggest the presence of shorter-timescale variations that occur on timescales of tens of millions of years, arguably driven by changes in intensity of sulfide oxidation in cycling of sulfur and/or by rapid changes in sulfur influx to the oceans and its associated sulfur isotopes. The Permian–Triassic boundary marks a transition in co-trajectories of δ34S and Δ33S from in-phase to anti-phase. The biogeochemical forcing that causes this is unclear. This newly calibrated record remains consistent with an earlier assertion ( Wu et al., 2010 ) that the sulfur isotope fractionation (Δ34SSW-PY) between oceanic sulfate (δ34SSW) and coeval sedimentary pyrite (δ34SPY) was smaller during the Paleozoic than in the Cenozoic, and reached lowest values during the Carboniferous. The δ34SIN and Δ33SIN estimates of influx sulfur to the oceans afforded by the isotope mass balance model for each geologic period throughout the Paleozoic reveal a change from higher positive values of δ34SIN (more negative values of Δ33SIN, approximately − 0.030 ‰ ) to lower positive values of δ34SIN (slightly negative values of Δ33SIN, approximately − 0.003 ‰ ). This change is interpreted to reflect the evolution of the Earth surface sulfur pool and the rapid recycling of newly formed evaporite sulfate minerals, as arguably supported by our estimates of integrated erosion rates over geologic time for pyrite and evaporite ( ( 6.1 – 6.4 ) × 10 − 9 a − 1 , and ( 7.7 – 7.8 ) × 10 − 9 a − 1 , respectively).

The H6N1 subtype avian influenza virus (AIV) is a zoonotic infectious disease pathogen, which poses a threat to human health. In order to study the possible substitution of H6N1 AIV for mammals, an avian-origin H6N1 virus was successively passaged in mice. The results showed that PB2 (L193H and E627K), PA (S709F) and HA (V127I) proteins had multiple amino acid substitutions. The virulence of the mouse-adapted virus was stronger than that of the wild virus, and it was highly pathogenic to mice. Therefore, continued surveillance of these substitutions in poultry H6N1 viruses is required.

Summary Background Human infection with avian influenza A H7N9 virus emerged in eastern China in February, 2013, and has been associated with exposure to poultry. We report the clinical and microbiological features of patients infected with influenza A H7N9 virus and compare genomic features of the human virus with those of the virus in market poultry in Zhejiang, China. Methods Between March 7 and April 8, 2013, we included hospital inpatients if they had new-onset respiratory symptoms, unexplained radiographic infiltrate, and laboratory-confirmed H7N9 virus infection. We recorded histories and results of haematological, biochemical, radiological, and microbiological investigations. We took throat and sputum samples, used RT-PCR to detect M, H7, and N9 genes, and cultured samples in Madin-Darby canine kidney cells. We tested for co-infections and monitored serum concentrations of six cytokines and chemokines. We collected cloacal swabs from 86 birds from epidemiologically linked wet markets and inoculated embryonated chicken eggs with the samples. We identified and subtyped isolates by RT-PCR sequencing. RNA extraction, complementary DNA synthesis, and PCR sequencing were done for one human and one chicken isolate. We characterised and phylogenetically analysed the eight gene segments of the viruses in the patient's and the chicken's isolates, and constructed phylogenetic trees of H, N, PB2, and NS genes. Findings We identified four patients (mean age 56 years), all of whom had contact with poultry 3–8 days before disease onset. They presented with fever and rapidly progressive pneumonia that did not respond to antibiotics. Patients were leucopenic and lymphopenic, and had impaired liver or renal function, substantially increased serum cytokine or chemokine concentrations, and disseminated intravascular coagulation with disease progression. Two patients died. Sputum specimens were more likely to test positive for the H7N9 virus than were samples from throat swabs. The viral isolate from the patient was closely similar to that from an epidemiologically linked market chicken. All viral gene segments were of avian origin. The H7 of the isolated viruses was closest to that of the H7N3 virus from domestic ducks in Zhejiang, whereas the N9 was closest to that of the wild bird H7N9 virus in South Korea. We noted Gln226Leu and Gly186Val substitutions in human virus H7 (associated with increased affinity for α-2,6-linked sialic acid receptors) and the PB2 Asp701Asn mutation (associated with mammalian adaptation). Ser31Asn mutation, which is associated with adamantane resistance, was noted in viral M2. Interpretation Cross species poultry-to-person transmission of this new reassortant H7N9 virus is associated with severe pneumonia and multiorgan dysfunction in human beings. Monitoring of the viral evolution and further study of disease pathogenesis will improve disease management, epidemic control, and pandemic preparedness. Funding Larry Chi-Kin Yung, National Key Program for Infectious Diseases of China.

This study examines the sulfur isotope record of seawater sulfate proxies using δ34S and Δ33S to place constraints on the average global fractionation (Δ34Spy) associated with pyrite formation and burial and the exponent λ that relates variations of the 34S/32S to variations of the 33S/32S. The results presented here use an analysis of the sulfur isotope record from seawater sulfate proxies and sedimentary sulfide to extract this quantity as the arithmetic difference between δ34S of seawater sulfate and contemporaneous sulfide. It also uses an independent method that draws on inferences about the Δ33S evolution of seawater sulfate to evaluate this further. These two methods yield similar results suggesting that Δ34Spy and λ changed over the course of the Phanerozoic from slightly lower values of Δ34Spy (lower values of λ) in the early Phanerozoic (Cambrian–Permian) to higher values of Δ34Spy (higher values of λ) starting in the Triassic. This change of Δ34Spy and the exponent λ is interpreted to reflect a change in the proportion of sulfide that was reoxidized and processed by bacterial disproportionation on a global scale. The revised record of Δ34Spy also yields model pyrite burial curves making them more closely resemble model evolution curves for other element systems and global sea level curves. It is suggested that possible links to sea level may occur via changes in the area of submerged continental shelves which would provide additional loci for pyrite burial. The slightly different constraints used by the two approaches to calculate this fractionation may allow for additional information to be obtained about the sulfur cycle with future studies. For instance, the correspondence of these results suggests that the inferred variation of 34S/32S of pyrite is real, and that there is no significant missing sink of fractionated sulfur at the resolution of the present study (such as might be associated with organic sulfur). Burial of organic sulfur may, however, have been important at some times in the Phanerozoic and shorter timescale deviations between results provided by these methods may be observed with higher resolution sampling. If observed, this would suggest either that the record for pyrite (or less likely sulfate) is biased, or that another sink (possibly as organic sulfur) was important during these times in the Phanerozoic.

The epidemiology and strain features of Kaposi's sarcoma-associated herpesvirus (KSHV) in transplant recipients and HIV-infected patients in China is not well described.To determine KSHV seroprevalence and characterize strains of KSHV in transplant recipients and HIV-infected patients in China.Patients were screened for KSHV infection using a KSHV open reading frame (ORF) 65 recombinant protein-dependent ELISA. The 172bp fragment of KSHV ORF26 was amplified by nested PCR and bilaterally sequenced from KSHV-seropositive peripheral blood mononuclear cells. ORF26 gene diversity and cladograms were analyzed and compared to predominant international strains.KSHV seroprevalence in renal transplant recipients [41% (44/107)] and HIV-infected patients [39% (29/74)] were significantly higher than in healthy people [13% (16/122)] (P0.01), but KSHV seroprevalence in liver transplant recipients [15% (5/33)] was similar to that of healthy people (P0.05). ORF26 DNA was detected in 47% (23/49) of KSHV-seropositive organ transplant recipients; 28% (8/29) of KSHV-seropositive HIV-infected patients; and 19% (3/16) of KSHV-seropositive healthy people. Organ transplant recipients had a significantly higher rate of KSHV DNAemia than healthy people (P0.05). The 13 KSHV strains that were analyzed were genetically close to the Hungary AY707887 strain and belonged to the A3 subtype.The seroprevalence of KSHV was elevated in renal transplant recipients and HIV-infected patients in China, and KSHV DNAemia was more common in these patients and liver transplant recipients. KSHV strains from Zhejiang Province belonged to the A3 subtype.

Background: The etiologic agent of severe acute respiratory syndrome (SARS) is a recently identified, positive single-stranded RNA (ssRNA) coronavirus (SARS-CoV). Little is known about the dynamic changes of the viral replicative form in SARS cases. Objectives: Evaluate whether SARS-CoV can infect and replicate in peripheral blood mononuclear cells (PBMCs) of infected persons and reveal any dynamic changes to the virus during the course of the disease. Study design: Peripheral blood mononuclear cells collected from SARS cases infected by the same infectious source were tested for both negative-stranded RNA (minus-RNA, “replicative intermediates”) and positive-stranded RNA (genomic RNA) of SARS-CoV during the course of hospitalization by reverse transcription-polymerase chain reaction (RT-PCR). Results: SARS-CoV minus-RNA was detected in PBMCs from SARS patients. The viral replicative forms in PBMCs were detectable during a period of 6 days post-onset of the disease, while the plus-RNA were detectable for a longer period (8–12 days post-onset). Conclusions: SARS-coronavirus can infect and replicate within PBMCs of SARS patients, but viral replication in PBMCs seems subject to self-limitation.