Pathogenic variations in MAML2 and MAMLD1 contribute to congenital hypothyroidism due to dyshormonogenesis by regulating the Notch signalling pathway.

BACKGROUND: In several countries, thyroid dyshormonogenesis is more common than thyroid dysgenesis in patients with congenital hypothyroidism (CH). However, known pathogenic genes are limited to those directly involved in hormone biosynthesis. The aetiology and pathogenesis of thyroid dyshormonogenesis remain unknown in many patients. METHODS: To identify additional candidate pathogenetic genes, we performed next-generation sequencing in 538 patients with CH and then confirmed the functions of the identified genes in vitro using HEK293T and Nthy-ori 3.1 cells, and in vivo using zebrafish and mouse model organisms. RESULTS: We identified one pathogenic MAML2 variant and two pathogenic MAMLD1 variants that downregulated canonical Notch signalling in three patients with CH. Zebrafish and mice treated with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butylester, a γ-secretase inhibitor exhibited clinical manifestations of hypothyroidism and thyroid dyshormonogenesis. Through organoid culture of primary mouse thyroid cells and transcriptome sequencing, we demonstrated that Notch signalling within thyroid cells directly affects thyroid hormone biosynthesis rather than follicular formation. Additionally, these three variants blocked the expression of genes associated with thyroid hormone biosynthesis, which was restored by HES1 expression. The MAML2 variant exerted a dominant-negative effect on both the canonical pathway and thyroid hormone biosynthesis. MAMLD1 also regulated hormone biosynthesis through the expression of HES3, the target gene of the non-canonical pathway. CONCLUSIONS: This study identified three mastermind-like family gene variants in CH and revealed that both canonical and non-canonical Notch signalling affected thyroid hormone biosynthesis.

Translation, cross-cultural adaptation, reliability, and validity of the Chinese version of the intensive care unit environment stress scale for pediatric patients.

PURPOSE: There is currently a lack of understanding of children's experience in the pediatric intensive care unit (PICU) environment. Additionally, pediatric patients may experience post-PICU syndrome following discharge. Thus, we aimed to adapt and evaluate the psychometric properties of a tool specifically for use with children in the PICU. DESIGN AND METHODS: According to Brislin's Model, the Intensive Care Unit Environment Stress Scale (ICUESS) was translated both forward and backward and adapted cross-culturally. A total of 210 PICU patients were selected from four hospitals in XXX to analyze the final translated version of the questionnaire, the Pediatric Intensive Care Unit Environmental Stress Scale (PICUESS). Content validity, exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) were used to assess the validity, while reliability was assessed using Cronbach's alpha and split-half reliability analysis. RESULTS: For PICUESS, seven of 42 items were modified. Content validity was high (overall = 0.96, item validity = 0.8 to 1.0). Exploratory factor analysis revealed eight common factors (Kaiser-Meyer-Olkin = 0.857, significant Bartlett's test). The results of the CFA indicate that the scale model fits well across the 8 factors. The entire scale demonstrated excellent internal consistency (Cronbach's alpha = 0.934). The overall split-half reliability was 0.935. CONCLUSIONS: The Chinese version of PICUESS demonstrates good reliability and validity, making it suitable for assessing pediatric patients' perceptions of the PICU environment. PRACTICE IMPLICATIONS: The PICUESS can assist healthcare professionals in providing personalized environment care for PICU patients. It has the potential to serve as a tool for further testing and international comparisons of pediatric patients' perceptions of the PICU environment.

Fungal genome size and composition reflect ecological strategies along soil fertility gradients.

Genomic traits reflect the evolutionary processes that have led to ecological variation among extant organisms, including variation in how they acquire and use resources. Soil fungi have diverse nutritional strategies and exhibit extensive variation in fitness along resource gradients. We tested for trade-offs in genomic traits with mycelial nutritional traits and hypothesize that such trade-offs differ among fungal guilds as they reflect contrasting resource exploitation and habitat preferences. We found species with large genomes exhibited nutrient-poor mycelium and low GC content. These patterns were observed across fungal guilds but with varying explanatory power. We then matched trait data to fungal species observed in 463 Australian grassland, woodland and forest soil samples. Fungi with large genomes and lower GC content dominated in nutrient-poor soils, associated with shifts in guild composition and with species turnover within guilds. These findings highlight fundamental mechanisms that underpin successful ecological strategies for soil fungi.

[Clinical characteristics of children with Omicron variant infection in Chengdu area, China]. / 成都地区Omicronå˜å¼‚æ ªæ„ŸæŸ“å„¿ç«¥çš„ä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To investigate the clinical characteristics of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Chengdu of China. METHODS: A retrospective analysis was conducted for the clinical data of 226 children who were infected with the Omicron variant of SARS-Cov-2 and were isolated and treated in Chengdu Shelter Hospital from August 28 to September 21, 2022. According to the presence or absence of clinical symptoms, they were divided into two groups: asymptomatic group and mild symptomatic group. The two groups were compared in terms of clinical characteristics, diagnosis and treatment, and prognosis. RESULTS: Among the 226 children infected with the Omicron variant, 71 (31.4%) were asymptomatic and 155 (68.6%) had mild symptoms. Fever and cough were the most common clinical symptoms, with fever in 95 children (61.3%) and cough in 92 children (59.4%). Of all 226 children, 188 (83.2%) received coronavirus disease 2019 (COVID-19) vaccination. The time to nucleic acid clearance ranged from 6 to 26 days, with a nucleic acid clearance rate of 58.0% (131/226). There were no significant differences among different age groups in sex, early symptoms, clinical typing, nucleic acid re-positive rate, nucleic acid clearance rate, and length of hospital stay (P>0.05). There were no significant differences between the asymptomatic and mild symptomatic groups in age, sex, underlying diseases, COVID-19 vaccination, use of Lianhua Qingwen granules, nucleic acid clearance rate, nucleic acid re-positive rate, and length of hospital stay (P>0.05). CONCLUSIONS: Children infected with the Omicron variant of SARS-Cov-2 in Chengdu generally have mild clinical symptoms, mainly upper respiratory tract infection, which has little threat to the health of children of different ages, and children tend to have a good overall prognosis.

Broad Impacts of Coronavirus Disease 2019 (COVID-19) Pandemic on Acute Respiratory Infections in China: An Observational Study.

BACKGROUND: To combat the coronavirus disease 2019 (COVID-19) pandemic, nonpharmaceutical interventions (NPIs) were implemented worldwide, which impacted a broad spectrum of acute respiratory infections (ARIs). METHODS: Etiologically diagnostic data from 142 559 cases with ARIs, who were tested for 8 viral pathogens (influenza virus [IFV], respiratory syncytial virus [RSV], human parainfluenza virus [HPIV], human adenovirus [HAdV], human metapneumovirus [HMPV], human coronavirus [HCoV], human bocavirus [HBoV], and human rhinovirus [HRV]) between 2012 and 2021, were analyzed to assess the changes in respiratory infections in China during the first COVID-19 pandemic year compared with pre-pandemic years. RESULTS: Test-positive rates of all respiratory viruses decreased during 2020, compared to the average levels during 2012-2019, with changes ranging from -17.2% for RSV to -87.6% for IFV. Sharp decreases mostly occurred between February and August when massive NPIs remained active, although HRV rebounded to the historical level during the summer. While IFV and HMPV were consistently suppressed year-round, RSV, HPIV, HCoV, HRV, and HBoV resurged and went beyond historical levels during September 2020-January 2021, after NPIs were largely relaxed and schools reopened. Resurgence was more prominent among children <18 years and in northern China. These observations remain valid after accounting for seasonality and long-term trend of each virus. CONCLUSIONS: Activities of respiratory viral infections were reduced substantially in the early phases of the COVID-19 pandemic, and massive NPIs were likely the main driver. Lifting of NPIs can lead to resurgence of viral infections, particularly in children.

Decline of onset-to-diagnosis interval and its impacts on clinical outcome of COVID-19 in China: a nation-wide observational study.

BACKGROUND: To quantitatively assess the impact of the onset-to-diagnosis interval (ODI) on severity and death for coronavirus disease 2019 (COVID-19) patients. METHODS: This retrospective study was conducted based on the data on COVID-19 cases of China over the age of 40 years reported through China's National Notifiable Infectious Disease Surveillance System from February 5, 2020 to October 8, 2020. The impacts of ODI on severe rate (SR) and case fatality rate (CFR) were evaluated at individual and population levels, which was further disaggregated by sex, age and geographic origin. RESULTS: As the rapid decline of ODI from around 40 days in early January to < 3 days in early March, both CFR and SR of COVID-19 largely dropped below 5% in China. After adjusting for age, sex, and region, an effect of ODI on SR was observed with the highest OR of 2.95 (95% CI 2.37‒3.66) at Day 10-11 and attributable fraction (AF) of 29.1% (95% CI 22.2‒36.1%) at Day 8-9. However, little effect of ODI on CFR was observed. Moreover, discrepancy of effect magnitude was found, showing a greater effect from ODI on SR among patients of male sex, younger age, and those cases in Wuhan. CONCLUSION: The ODI was significantly associated with the severity of COVID-19, highlighting the importance of timely diagnosis, especially for patients who were confirmed to gain increased benefit from early diagnosis to some extent.

Rapid and visual detection of Staphylococcus aureus in milk using a recombinase polymerase amplification-lateral flow assay combined with immunomagnetic separation.

AIMS: The aim of this study was to develop a novel approach using lateral flow recombinase polymerase amplification (RPA-LF) combined with immunomagnetic separation (IMS) for the rapid detection of Staphylococcus aureus in milk. METHODS AND RESULTS: Under optimum conditions, the average capture efficiency values for S. aureus strains (104 colony-forming units [CFU] per ml) was above 95.0% in PBST and ~80% in milk within 45 min with 0.7 mg immunomagnetic beads. The RPA-LF assay, which comprised DNA amplification via RPA at 39°C for 10 min and visualization of the amplicons through LF strips for 5 min, detected S. aureus within 15 min. The method only detected S. aureus and did not show cross-reaction with other bacteria, exhibiting a high level of specificity. Sensitivity experiments confirmed a detection limit of RPA-LF assay as low as 600 fg per reaction for the S. aureus genome (corresponding to approximately 36 CFU of S. aureus), which was about 16.7-fold more sensitive than that of the conventional polymerase chain reaction method. When RPA-LF was used in combination with IMS to detect S. aureus inoculated into artificially contaminated milk, it exhibited a detection limit of approximately 40 CFU per reaction. CONCLUSIONS: The newly developed IMS-RPA-LF method enabled detection of S. aureus at levels as low as 40 CFU per reaction in milk samples without culture enrichment for an overall testing time of only 70 min. SIGNIFICANCE AND IMPACT OF THE STUDY: The newly developed IMS-lateral flow RPA-LF assay effectively combines sample preparation, amplification and detection into a single platform. Because of its high sensitivity, specificity and speed, the IMS-RPA-LF assay will have important implications for the rapid detection of S. aureus in contaminated food.

The imported infections among foreign travelers in China: an observational study.

BACKGROUND: In the past few decades, globalization has rendered more frequent and intensive population movement between countries, which has changed the original disease spectrum and brought a huge health impact on the global population including China. This study aims to describe the spectrum and epidemiological characteristics of imported infections among foreign travelers travelling to China. METHODS: The data on imported infections among foreign travelers were obtained from Custom Inbound Screening System (CISS) and the National Notifiable Infectious Disease Reporting System (NNIDRS). All the infections were classified into respiratory, gastrointestinal, vector-borne, blood/sex-transmitted and mucocutaneous diseases, of which case numbers and incidences were calculated and the proportions were compared among subgroups. RESULTS: In total, 17,189 travelers diagnosed with 58 imported infectious diseases were reported from 2014 to 2018, with an overall incidence of 122.59 per million. Respiratory infection (7,351 cases, mainly influenza) and blood/sex-transmitted diseases (6,114 cases mainly Hepatitis B and HIV infection) were the most frequently diagnosed diseases, followed by vector-borne infections (3,128 cases, mainly dengue fever and malaria). The highest case number was from Asia and Europe, while the highest incidence rate was from Africa (296.00 per million). When specific diagnosis was compared, both the highest absolute case number and incidence were observed for influenza. An obvious seasonal pattern was observed for vector-borne diseases, with the annual epidemic spanning from July to November. The origin-destination matrices disclosed the movement of imported infection followed specific routes. CONCLUSIONS: Our study provided a profile of infectious diseases among foreign travelers travelling to China and pinpointed the target regions, seasons and populations for prevention and control, to attain an informed control of imported infections in China.

Endoscopic resection in combination with ligation for the treatment of duodenal subepithelial lesions: a single-center experience.

INTRODUCTION AND AIM: duodenal subepithelial lesions (SELs) are increasingly detected during endoscopic examinations. However, no feasible and safe methods are available to remove duodenal SELs. The present study aimed to assess the feasibility and safety of endoscopic resection in combination with ligation (ER-L) for the removal of duodenal SELs. PATIENTS AND METHODS: a total of 101 patients with duodenal SELs underwent ER-L from February 2010 to February 2020. The primary outcomes were complete resection, en bloc resection and R0 resection. The secondary outcomes included procedure duration, bleeding, perforation and residual lesions. A total of 101 patients with 101 duodenal SELs (ranged from 8.4 mm to 20.2 mm in size) were included in the study. RESULTS: most of the SELs (95.1 %) originated from the submucosal layer and were successfully removed using ER-L. The rates of complete resection, en bloc resection and R0 resection were 100 %, 96.0 % and 88.1 %, respectively. The median procedure duration was eight minutes. There were no severe complications, except for four patients who developed post-procedure bleeding (4.0 %) and recovered after conservative treatment. Furthermore, no residual lesions were detected during the follow-up period (median of 36 months). In fact, logistic regression analysis showed that the size of duodenal SELs was an independent factor for R0 resection during the ER-L procedure. CONCLUSION: in conclusion, ER-L is feasible and safe to remove duodenal SELs that originate from the submucosal layer and are less than 20 mm. However, the feasibility and safety of the ER-L should be further confirmed when removing the duodenal SELs that originate from the muscularis propria (MP) layer and are larger than 20 mm in diameter.

[A Case of Congenital Tufting Enteropathy with EpCAM Gene Complex Heterozygous Mutation (c.491+1G>A; c.352_353ins CACC)].

The patient, a one-month-old male infant, was admitted for "recurrent diarrhea for 20 + days and vomiting for 4 days". On the 8th day after birth, the patient began to develop recurrent refractory diarrhea, accompanied by abdominal distension, vomiting, dehydration, acidosis, and malnutrition. There were many cases of malignant tumors of the digestive system in the patient's family. Genetic testing identified compound heterozygous mutations (c.491+1G>A; c.352_353ins CACC) in epithelial cell adhesion molecule (EpCAM) gene and the patient was hence diagnosed with congenital tufting enteropathy. The patient was given partial parenteral nutrition support. The patient's diarrheal symptom was improved, but it was difficult to increase the amount of formula because any increase in the amount of formula for the patient would inevitably result in abdominal distention and vomiting. The patient experienced repeated fever in the later period of hospitalization and was eventually discharged from the hospital with the family's signed consent. He still had diarrhea and vomiting after leaving the hospital. Four weeks after discharge, the patient lost about 1 kg of weight and eventually died.

[Value of metagenomic next-generation sequencing in children with hemophagocytic syndrome with central nervous system involvement]. / å®åŸºå› ç»„äºŒä»£æµ‹åºåœ¨ä¼´æœ‰ä¸­æž¢ç¥žç»ç³»ç»Ÿå—ç´¯å„¿ç«¥å™¬è¡€ç»†èƒžç»¼åˆå¾ä¸­çš„åº”ç”¨ä»·å€¼.

OBJECTIVES: To study the value of metagenomic next-generation sequencing (mNGS) in detecting intracranial Epstein-Barr virus (EBV) infection in children with hemophagocytic syndrome (HPS) with central nervous system involvement. METHODS: A retrospective analysis was performed for the cerebrospinal fluid mNGS results of 30 HPS children with central nervous system involvement, which were compared with the results of cerebrospinal fluid EBV-DNA detection and serum EBV antibody profile. The change in serum EBV-DNA copy number after treatment was used to evaluate the efficacy of targeted therapy. RESULTS: The positive rate of EBV in cerebrospinal fluid determined by mNGS was significantly higher than that of EBV-DNA in cerebrospinal fluid (100% vs 10%, P<0.001) and had no significant difference from the positive rate of serum EBV antibody profile (100% vs 93%, P>0.05). The median number of sequences determined by mNGS was 2 400, and serum EBV-DNA copy number before treatment was moderately positively correlated with the number of EBV sequences (rs=0.693, P<0.001). The multiple linear regression analysis showed that the number of sequences determined by mNGS in cerebrospinal fluid increased with the increase in serum EBV-DNA copy number before treatment (P<0.05). CONCLUSIONS: EBV-associated HPS often results in EBV-infected viral encephalitis, and mNGS can significantly increase the detection rate of EBV in cerebrospinal fluid, which may help with clinical diagnosis.

Association between fatality rate of COVID-19 and selenium deficiency in China.

BACKGROUND: COVID-19 has impacted populations around the world, with the fatality rate varying dramatically across countries. Selenium, as one of the important micronutrients implicated in viral infections, was suggested to play roles. METHODS: An ecological study was performed to assess the association between the COVID-19 related fatality and the selenium content both from crops and topsoil, in China. RESULTS: Totally, 14,045 COVID-19 cases were reported from 147 cities during 8 December 2019-13 December 2020 were included. Based on selenium content in crops, the case fatality rates (CFRs) gradually increased from 1.17% in non-selenium-deficient areas, to 1.28% in moderate-selenium-deficient areas, and further to 3.16% in severe-selenium-deficient areas (P = 0.002). Based on selenium content in topsoil, the CFRs gradually increased from 0.76% in non-selenium-deficient areas, to 1.70% in moderate-selenium-deficient areas, and further to 1.85% in severe-selenium-deficient areas (P < 0.001). The zero-inflated negative binomial regression model showed a significantly higher fatality risk in cities with severe-selenium-deficient selenium content in crops than non-selenium-deficient cities, with incidence rate ratio (IRR) of 3.88 (95% CIs: 1.21-12.52), which was further confirmed by regression fitting the association between CFR of COVID-19 and selenium content in topsoil, with the IRR of 2.38 (95% CIs: 1.14-4.98) for moderate-selenium-deficient cities and 3.06 (1.49-6.27) for severe-selenium-deficient cities. CONCLUSIONS: Regional selenium deficiency might be related to an increased CFR of COVID-19. Future studies are needed to explore the associations between selenium status and disease outcome at individual-level.

The differential demographic pattern of coronavirus disease 2019 fatality outside Hubei and from six hospitals in Hubei, China: a descriptive analysis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) epidemic has been largely controlled in China, to the point where case fatality rate (CFR) data can be comprehensively evaluated. METHODS: Data on confirmed patients, with a final outcome reported as of 29 March 2020, were obtained from official websites and other internet sources. The hospitalized CFR (HCFR) was estimated, epidemiological features described, and risk factors for a fatal outcome identified. RESULTS: The overall HCFR in China was estimated to be 4.6% (95% CI 4.5-4.8%, P < 0.001). It increased with age and was higher in males than females. Although the highest HCFR observed was in male patients ≥70 years old, the relative risks for death outcome by sex varied across age groups, and the greatest HCFR risk ratio for males vs. females was shown in the age group of 50-60 years, higher than age groups of 60-70 and ≥ 70 years. Differential age/sex HCFR patterns across geographical regions were found: the age effect on HCFR was greater in other provinces outside Hubei than in Wuhan. An effect of longer interval from symptom onset to admission was only observed outside Hubei, not in Wuhan. By performing multivariate analysis and survival analysis, the higher HCFR was associated with older age (both P < 0.001), and male sex (both P < 0.001). Only in regions outside Hubei, longer interval from symptom onset to admission, were associated with higher HCFR. CONCLUSIONS: This up-to-date and comprehensive picture of COVID-19 HCFR and its drivers will help healthcare givers target limited medical resources to patients with high risk of fatality.

Epidemiological features of COVID-19 patients with prolonged incubation period and its implications for controlling the epidemics in China.

BACKGROUND: COVID-19 patients with long incubation period were reported in clinical practice and tracing of close contacts, but their epidemiological or clinical features remained vague. METHODS: We analyzed 11,425 COVID-19 cases reported between January-August, 2020 in China. The accelerated failure time model, Logistic and modified Poisson regression models were used to investigate the determinants of prolonged incubation period, as well as their association with clinical severity and transmissibility, respectively. RESULT: Among local cases, 268 (10.2%) had a prolonged incubation period of > 14 days, which was more frequently seen among elderly patients, those residing in South China, with disease onset after Level I response measures administration, or being exposed in public places. Patients with prolonged incubation period had lower risk of severe illness (ORadjusted = 0.386, 95% CI: 0.203-0.677). A reduced transmissibility was observed for the primary patients with prolonged incubation period (50.4, 95% CI: 32.3-78.6%) than those with an incubation period of ≤14 days. CONCLUSIONS: The study provides evidence supporting a prolonged incubation period that exceeded 2 weeks in over 10% for COVID-19. Longer monitoring periods than 14 days for quarantine or persons potentially exposed to SARS-CoV-2 should be justified in extreme cases, especially for those elderly.

Efficacy of low-dose versus high-dose simethicone with polyethylene glycol for bowel preparation: A prospective randomized controlled trial.

BACKGROUND AND AIM: Additional simethicone (SIM) can improve adequate bowel preparation and adenoma detection rate (ADR). However, there is no consensus on the optimal dose of SIM. In this study, we compared the adequate bowel preparation rate with supplementation of split-dose 2 L polyethylene glycol (PEG) with low-dose SIM (200 mg) versus high-dose SIM (1200 mg). METHODS: This was a prospective, randomized, observer-blinded trial involving consecutive subjects undergoing colonoscopy. The primary outcome was adequate bowel preparation as assessed by Boston Bowel Preparation Scale (BBPS) score. RESULTS: Four hundred subjects were randomly allocated to low-dose SIM or high-dose SIM group. Baseline characteristics were comparable in the two groups (P > 0.05). No significant between-group differences were observed with respect to total bubble scale (BS) (8.49 ± 1.00 vs 8.39 ± 1.10, P = 0.07), total BBPS score (8.70 ± 0.81 vs 8.29 ± 1.18, P = 0.98), ADR (33.68% vs 31.79%, P = 0.69) or withdrawal time (13 [range, 10-16] min vs 13 [10-15] min, P = 0.96). The intubation time in low-dose SIM group was significantly shorter than that in high-dose SIM group (8 (4-16) min vs 10 [6-17] min, P = 0.04). In addition, BS scores as well as diminutive ADR in right colon were superior in the low-dose SIM group (2.68 ± 0.59 vs 2.52 ± 0.73, P = 0.03 and 54.29% vs 30.30%, P = 0.046, respectively). CONCLUSION: Addition of low-dose SIM to split-dose 2 L PEG was as effective as addition of high-dose SIM with respect to adequate bowel preparation, ADR and patient tolerance. However, low-dose SIM was superior with respect to intubation time, right colon BS scores, right colon diminutive ADR and cost savings.

Epidemiological parameters of COVID-19 and its implication for infectivity among patients in China, 1 January to 11 February 2020.

BackgroundThe natural history of disease in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remained obscure during the early pandemic.AimOur objective was to estimate epidemiological parameters of coronavirus disease (COVID-19) and assess the relative infectivity of the incubation period.MethodsWe estimated the distributions of four epidemiological parameters of SARS-CoV-2 transmission using a large database of COVID-19 cases and potential transmission pairs of cases, and assessed their heterogeneity by demographics, epidemic phase and geographical region. We further calculated the time of peak infectivity and quantified the proportion of secondary infections during the incubation period.ResultsThe median incubation period was 7.2 (95% confidence interval (CI): 6.9‒7.5) days. The median serial and generation intervals were similar, 4.7 (95% CI: 4.2‒5.3) and 4.6 (95% CI: 4.2‒5.1) days, respectively. Paediatric cases < 18 years had a longer incubation period than adult age groups (p = 0.007). The median incubation period increased from 4.4 days before 25 January to 11.5 days after 31 January (p < 0.001), whereas the median serial (generation) interval contracted from 5.9 (4.8) days before 25 January to 3.4 (3.7) days after. The median time from symptom onset to discharge was also shortened from 18.3 before 22 January to 14.1 days after. Peak infectivity occurred 1 day before symptom onset on average, and the incubation period accounted for 70% of transmission.ConclusionThe high infectivity during the incubation period led to short generation and serial intervals, necessitating aggressive control measures such as early case finding and quarantine of close contacts.

Impacts of leguminous shrub encroachment on neighboring grasses include transfer of fixed nitrogen.

Shrub encroachment induced by global change and human disturbance strongly affects ecosystem structure and function. In this study, we explore the degree to which invading leguminous shrubs affected neighboring grasses, including via the transfer of fixed nitrogen (N). We measured N concentrations and natural abundance (15)N of shoot tissues from three dominant grasses from different plant functional groups across seven distances along a local transect (up to 500 cm) to the leguminous shrub, Caragana microphylla. C. microphylla did transfer fixed N to neighboring grasses, but the amount and distance of N transferred were strongly species-specific. Shoot N concentrations decreased significantly with distance from C. microphylla, for a rhizomatous grass, Leymus chinensis, and a bunchgrass, Achnatherum sibiricum. However, N concentrations of another bunchgrass, Stipa grandis, were higher only directly underneath the shrub canopy. Shoot δ(15)N values of L. chinensis were enriched up to 500 cm from the shrub, but for S. grandis were enriched only below the shrub canopy. In contrast, δ(15)N of A. sibiricum did not change along the 500-cm transect. Our results indicated the rhizomatous grass transferred fixed N over long distances while bunchgrasses did not. The presence of C. microphylla increased the shoot biomass of L. chinensis but decreased that of S. grandis and A. sibiricum. These findings highlight the potential role of nutrient-acquisition strategies of neighboring grasses in moderating the interspecific variation of fixed N transfer from the leguminous shrub. Overall, leguminous shrubs have either positive or negative effects on the neighboring grasses and dramatically affect plant community composition and structure.

Dressed-state realization of the transition from electromagnetically induced transparency to Autler-Townes splitting in superconducting circuits.

We investigate electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) in a driven three-level superconducting artificial system which is a dressed-state system resulting from the coupling of a superconducting charge qubit (an artificial atom) and a transmission line resonator. In the frame of the dressed-state approach and steady-state approximation, we study the linear absorption of the dressed artificial system to a weak probe signal in depth. In light of the spectrum-decomposition method and some other restrictions, we obtain the explicit conditions for the dressed-state realization of EIT and ATS and present a corresponding "phase diagram". In contrast to usual bare systems, these conditions given in the dressed system have an extra dependency on the qubit-resonator parameters. And by varying the qubit's Josephson coupling energy we demonstrate a transition from EIT to ATS.

Coexistence of three-wave, four-wave, and five-wave mixing processes in a superconducting artificial atom.

We present a theoretical study of multiwave mixing in a driven superconducting quantum qubit (artificial atom) with a cyclic Ξ-type three-level structure. We first show that three-wave mixing (3WM), four-wave mixing (4WM), and five-wave mixing (5WM) processes can coexist in the microwave regime in such an artificial system due to the absence of selection rules. Because of electromagnetically induced transparency suppression of linear absorption in a standard Ξ-type configuration, the generated 4WM is enhanced greatly and its efficiency can be as high as 0.1% for only a single artificial atom. We also show that Autler-Townes splitting occurs in the 3WM and 5WM spectra and quantum interference has a significant impact on the total signal intensity being a coherent superposition of these two signals.