The transmissibility estimation of influenza with early stage data of small-scale outbreaks in Changsha, China, 2005-2013.

Hundreds of small-scale influenza outbreaks in schools are reported in mainland China every year, leading to a heavy disease burden which seriously impacts the operation of affected schools. Knowing the transmissibility of each outbreak in the early stage has become a major concern for public health policy-makers and primary healthcare providers. In this study, we collected all the small-scale outbreaks in Changsha (a large city in south central China with ~7·04 million population) from January 2005 to December 2013. Four simple and popularly used models were employed to calculate the reproduction number (R) of these outbreaks. Given that the duration of a generation interval Tc = 2·7 and the standard deviation (s.d.) σ = 1·1, the mean R estimated by an epidemic model, normal distribution and delta distribution were 2·51 (s.d. = 0·73), 4·11 (s.d. = 2·20) and 5·88 (s.d. = 5·00), respectively. When Tc = 2·9 and σ = 1·4, the mean R estimated by the three models were 2·62 (s.d. = 0·78), 4·72 (s.d. = 2·82) and 6·86 (s.d. = 6·34), respectively. The mean R estimated by gamma distribution was 4·32 (s.d. = 2·47). We found that the values of R in small-scale outbreaks in schools were higher than in large-scale outbreaks in a neighbourhood, city or province. Normal distribution, delta distribution, and gamma distribution models seem to more easily overestimate the R of influenza outbreaks compared to the epidemic model.

Dynamic modelling of strategies for the control of acute haemorrhagic conjunctivitis outbreaks in schools in Changsha, China (2004-2015).

Outbreaks of acute haemorrhagic conjunctivitis (AHC) - a rapidly progressing and highly contagious infection - often occur in schools during summer and autumn. We used dynamic modelling to evaluate the efficacy of interventions to control AHC outbreaks in schools. A susceptible-infected-recovered (SIR) model was built to simulate AHC outbreaks in Chinese schools, with isolation or school closure added into the model. We used outbreak data from the period 2004-2015 in our models to estimate the effective reproduction number and assess the efficacy of interventions. The median effective reproduction number (uncontrolled) of AHC outbreaks was 7·00 (range 1·77-25·87). The median effective reproduction number (controlled) of AHC outbreaks was 0·16 (range 0·00-2·28). Intervention efficacy is affected by the timing of isolation; earlier isolation is associated with a lower morbidity peak and smaller total attack rate (TAR). School closures were not effective; TARs were almost 100% and did not change even when different school closure durations were adopted. Isolation and school closure as a combined intervention strategy was used to simulate outbreak control, but the efficacy was the same as isolation alone. An isolation programme could be an effective primary intervention during AHC outbreaks in schools. However, school closure is not recommended.

Postradiation dermatofibrosarcoma protuberans : case report and literature review.

Radiotherapy has long been known to induce soft tissue sarcomas. However, there are only six cases of postradiation dermatofibrosarcoma protuberans (DFSP) reported in the literature, and no case in Asians has been reported so far. Herein, we report a case of DFSP, confirmed by immunohistochemistry, which developed on the old scar at the irradiated right chest wall of an Asian woman. We performed a radical surgical excision of the lesion and covered the defect with latissimus dorsi island myocutaneous flap followed the surgical treatment. 12 months postoperatively, the patient leads a good result without signs of recurrence.

Postradiation Dermatofibrosarcoma Protuberans: Case Report and Literature Review.

Radiotherapy has long been known to induce soft tissue sarcomas. However, there are only six cases of post-radiation dermatofibrosarcoma protuberans (DFSP) reported in the literature, and no case in Asians has been reported so far. Herein, we report a case of DFSP, confirmed by immunohistochemistry, which developed on the old scar at the irradiated right chest wall of an Asian woman. We performed a radical surgical excision of the lesion and covered the defect with latissimus dorsi island myocutaneous flap followed the surgical treatment. 12 months postoperatively, the patient leads a good result without signs of recurrence.

Non-ohmic behavior of carrier transport in highly disordered graphene.

We report measurements of disordered graphene probed by both a high electric field and a high magnetic field. By applying a high source-drain voltage, Vsd, we are able to study the current-voltage relation I-Vsd of our device. With increasing Vsd, a crossover from the linear I-Vsd regime to the non-linear one, and eventually to activationless-hopping transport occurs. In the activationless-hopping regime, the importance of Coulomb interactions between charged carriers is demonstrated. Moreover, we show that delocalization of carriers which are strongly localized at low T and at small Vsd occurs in the presence of high electric field and perpendicular magnetic field.

All-electrical injection and detection of a spin-polarized current using 1D conductors.

All-electrical control of spin transport in nanostructures has been the central interest and challenge of spin physics and spintronics. Here we demonstrate on-chip spin polarizing or filtering actions by driving the gate-defined one dimensional (1D) conductor, one of the simplest geometries for integrated quantum devices, away from the conventional Ohmic regime. Direct measurement of the spin polarization of the emitted current was performed when the momentum degeneracy was lifted, wherein both the 1D polarizer for spin injection and the analyzer for spin detection were demonstrated. The results showed that a configuration of gates and applied voltages can give rise to a tunable spin polarization, which has implications for the development of spintronic devices and future quantum information processing.

[Analysis of clinical features and poor prognostic factors of acute hematogenous osteomyelitis in children].

Objective: To analyze the clinical characteristics, pathogenic bacteria, complications and risk factors of prognosis of acute hematogenous osteomyelitis in children. Methods: The clinical manifestations, laboratorg tests, etiological charateristics and clinical data of 107 patients with acute hematogenous osteomyelitis admitted to Beijing Children's Hospital from January 2017 to December 2020 were retrospectively analyzed. According to the drug sensitivity results of Staphylococcus aureus, the group was divided into methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) group; according to the presence or absence of complications, the group was divided into the group with and without complications; according to the prognosis of the follow-up children, the group was divided into good prognosis and poor prognosis. The χ2 test or Mann-Whitney U test used for comparison between groups, and Logistic regression was used to analyze the risk factors for complications and prognosis. Results: Of the 107 patients, 62 were males and 45 were females. The age of presentation was 5.6 (1.7, 10.0) years, including 5 patients (4.7%) age from >28 days to 3 months, 46 patients (43.0%) age from >3 months to 5 years, 43 patients (40.2%)>5-12 years of age, and 13 patients (12.1%)>12-18 years of age. The first symptoms were acute fever in 35 patients (32.7%), limb pain in 24 patients (22.4%), and fever with limb pain in 23 patients (21.5%). Pathogen culture was positive in 75 patients (70.1%), Streptococcus pyogenes, Salmonella enterica and Escherichia coli in 1 case (1.4%) each, and Staphylococcus aureus in 72 cases (96.0%), among them, 47 cases were MSSA, 22 cases were MRSA, and 3 cases had positive reports of Staphylococcus aureus from other hospitals without drug-sensitive tests. The proportion of infected children living in rural areas and receiving surgical treatment was higher in the MRSA group than in the MSSA group (14 cases (63.6%) vs. 18 cases (38.3%) and 21 cases (95.5%) vs. 33 cases (70.2%), χ2=3.87, 4.23, both P<0.05). Sixty-five children had no complications while 42 children (39.3%) suffered from complications. Common complications consisted of 19 cases (17.8%) of sepsis, 17 cases (15.9%) of septic arthritis, and 12 cases (11.2%) of venous thrombosis. The group with complications showed higher mental changes, decreased appetite and (or) weakness, positive pathogenic cultures, and time from admission to surgery than the group without complications (18 cases (42.9%) vs. 9 cases (13.8%), 20 cases (47.6%) vs. 12 cases (18.5%), 34 cases (81.0%) vs. 41 cases (63.1%), 3.5 (2.0, 6.0) vs. 2.0 (1.0, 4.0) d,χ2=11.38, 10.35, 3.89, Z=2.21, all P<0.05). The poor prognosis group had more comorbidities, combined local complications, and positive aureus than the good prognosis group (10/15 vs. 34.9% (30/86), 7/15 vs. 17.4% (15/86), 14/15 vs. 61.6% (53/86), χ2=5.39, 6.40, 4.42, all P<0.05). Multifactorial Logistic regression analysis showed that acute phase C-reactive protein (CRP) was both an independent risk factor for complications (OR=1.01, 95%CI 1.01-1.02) and an independent risk factor for poor prognosis (OR=1.01, 95%CI 1.00-1.02). Conclusions: The first symptoms of acute hematogenous osteomyelitis are acute fever, limb pain, and fever with limb pain are most common. Staphylococcus aureus is the most common pathogenic organism. Those with loss of appetite and (or) weakness, mental changes, positive pathogenic cultures, and longer time between admission and surgery are prone to complications. Those with complications, combined local complications, and positive for Staphylococcus aureus had a poor prognosis. Elevated CRP is an independent risk factor not only for complications but for poor prognosis as well.

[Progress in research of 2019-nCoV infection in children and adolescents].

As 2019-nCoV vaccine is widely used in the adult population, children and adolescents have gradually become an important susceptible population to 2019-nCoV due to their low coverage of the vaccine and high contact degree. Understanding the characteristics of 2019-nCoV infection in minors is vital. This paper summarized the progress in the research of 2019-nCoV in minors by using the data from the retrieval of recently published literature. Furthermore, the key characteristics of 2019-nCoV infection in minors, including the susceptibility, transmissibility, prognosis and immune response were analyzed and the progress in child and adolescent vaccine development was introduced.

Reappraisal of the importance of mutations in the NS5A-PKR-binding domain of hepatitis C-1b virus in the era of optimally individualized therapy.

Past studies have reported that mutations in the protein kinase R-binding domain (PKRBD) sequences of hepatitis C virus (HCV) NS5A proteins are correlated with response to fixed-duration interferon (IFN)-based therapy in patients infected with HCV-1b. In this study, we investigated whether the substitutions in PKRBD, including the IFN sensitivity-determining region (ISDR) and 26 additional downstream amino acids from ISDR, will have effects upon patients infected with chronic HCV-1b in the era of individualized therapy with peginterferon and ribavirin. Thirty-seven patients were treated with optimally tailored therapy guided by baseline viral load combined with rapid and early virological responses while 23 patients were treated without guidance and/or assigned suboptimal treatment duration. The amino acid sequences of the PKRBD were determined by PCR and sequencing. The overall sustained virological response (SVR) rate of patients who received optimally individualized therapy was 78.4%, which was better than the SVR rate of patients who received suboptimal therapy (47.8%, P = 0.015). Multivariate analysis showed that optimally individualized therapy (P = 0.019) and 80/80/80 adherence (P = 0.006) were independent favourable predictors of SVR in the entire cohort. Further sub-analysis of the predictive factors of SVR in patients treated with optimally individualized therapy showed that mutations in the 26-amino acid downstream from the ISDR (P = 0.024) were the only independent predictor of SVR. We concluded that mutations in 26-amino acid downstream portion from the ISDR remained a prognosticator of SVR in the era of optimally tailored therapy.

Direct observation of nonequilibrium spin population in quasi-one-dimensional nanostructures.

Observation of the interplay between interacting energy levels of two spin species is limited by the difficulties in continuously tracking energy levels and thus leaves spin transport in quantum wires still not well understood. We present a dc conductance feature in the nonequilibrium transport regime, a direct indication that the first one-dimensional subband is filled mostly by one spin species only. How this anomalous spin population changes with magnetic field and source-drain bias is directly measured. We show the source-drain bias changes spin polarization in semiconductor nanowires, providing a fully electrical method for the creation and manipulation of spin polarization as well as spin-polarized currents.

[Characteristics and recovery of hearing loss in 573 patients with bacterial meningitis].

Objective: To analyze the characteristics and prognosis of hearing loss in children with bacterial meningitis. Methods: This was a single-center retrospective cohort study. Patients diagnosed with bacterial meningitis who were hospitalized in Beijing Children's Hospital between 2010 and 2016 and older than 28 days and younger than 18 years at symptom onset were included in this study (n=573). All clinical information including hearing assessment results during hospitalization were reviewed. All patients with hearing loss were followed up to repeat their hearing test and assess their hearing condition with parents' evaluation of aural and (or) oral performance of children (PEACH). Patients were grouped according to their hearing assessment results, and Logistic regression analysis was used to analyze the risk factors for hearing loss in patients with bacterial meningitis. Results: Five hundred and seventy-three patients were enrolled in this study, including 347 males and 226 females. The onset age ranged from 29 days to 15.8 years. Two hundred and forty-six patients had identified causative pathogens, among whom 92 cases (37.4%) were pneumococcal meningitis cases. Hearing loss was found in 160 cases (27.9%) during hospitalization, involving 240 ears. Permanent hearing loss was found in 20 cases (16.9%), involving 32 ears. In the patients with permanent hearing loss, 87.5% (28/32) of ears were identified as severe or profound hearing loss during hospitalization. Logistic regression analysis showed that dystonia, the protein concentration level in cerebrospinal fluid>1 g/L, glucose concentration level lower than 1 mmol/L and subdural effusion were independent risk factors for hearing loss (OR=2.426 (1.450-4.059), 1.865 (1.186-2.932), 1.544 (1.002-2.381) and 1.904 (1.291-2.809)). Conclusions: Hearing loss is a common sequela of bacterial meningitis in children. Most patients have transient hearing loss, but patients with severe or profound hearing impairment have a higher risk of developing permanent hearing loss.

Unit cost of Mohs and Dermasurgery Unit.

BACKGROUND: Appropriate pricing for medical services of not-for-profit hospital is necessary. The prices should be fair to the public and should be high enough to cover the operative costs of the organization. OBJECTIVE: The purpose of this study was to determine the cost and unit cost of medical services performed at the Mohs and Dermasurgery Unit (MDU), Department of Dermatology, The University of Texas-MD Anderson Cancer Center, Houston, TX from the healthcare provider's perspective. METHODS: MDU costs were retrieved from the Financial Department for fiscal year 2006. The patients' statistics were acquired from medical records for the same period. Unit cost calculation was based on the official method of hospital accounting. RESULTS: The overall unit cost for each patient visit was $673.99 United States dollar (USD). The detailed unit cost of nurse visit, new patient visit, follow-up visit, consultation, Mohs and non-Mohs procedure were, respectively, $368.27, $580.09, $477.82, $585.52, $1,086.12 and $858.23 USD. With respect to a Mohs visit, the unit cost per lesion and unit cost per stage were $867.89 and $242.30 USD respectively. CONCLUSIONS: Results from this retrospective study provide information that may be used for pricing strategy and resource allocation by the administrative board of MDU.

[Clinical and pathological features of 13 children with Epstein-Barr virus-positive lymphoproliferative disease].

Objective: To summarize the clinical characteristics, virological and histopathological features, clinical outcome of Epstein-Barr virus-positive lymphoproliferative disease (EBV(+)LPD) in children. Methods: The clinical and follow-up data of 13 children histopathologically diagnosed as EBV(+)LPD in the Department of Infectious Disease of Beijing Children's Hospital between January 2011 and December 2016 were summarized. Results: Of the 13 patients, 5 were males and 8 females. The median age of disease onset was 6.0 years (range 1.3 to 15.0 years). The median duration between disease onset and diagnosis was 3 months (range 1 to 24 months). All the 13 patients had fever, 9 cases had hepatosplenomegaly and lymphoadenopathy, 4 cases had only lymphoadenopathy, 7 cases had reduced peripheral blood cells, 7 cases had lung involvement, 3 cases had central nervous system involvement, 3 cases had cardiac involvement, 3 cases had intestinal involvement, 2 cases had skin involvement and 1 case had abdominal mass. All the 13 patients underwent whole blood EBV-DNA PCR examination and the copies ranged from 1×10(8)/L to 1×10(11)/L. Pathology of lymph node confirmed 6 cases, skin pathology confirmed 2 cases, lung pathology, ileum mucosa pathology, liver pathology, abdominal mass pathology and bone marrow pathology confirmed 1 case each. Among 13 patients, 9 cases presented with EBV-positive T cell lymphoproliferative disease(EBV(+) T-LPD), 2 cases with hydroa vacciniforme (HV) and 2 cases with EBV-positive diffuse large B-cell lymphoma (EBV(+) DLBCL) . All the patients were followed up for 2 days to 65 months after discharge. Among 9 cases of EBV(+)T-LPD, 1 case died in a short time, 1 case died after evolved to T-cell lymphoma, 2 cases recovered after hematopoietic stem cell transplantation, 1 case recovered after the chemotherapy of hemophagocytic lymphohistiocytosis(HLH) 2004 protocol and 4 cases were stable now. Of 2 cases of HV patients, 1 case died after evolved to HV like lymphoma and the other still have symptoms. Among 2 cases of EBV(+) DLBCL, 1 case died shortly after discharge and the other was still stable after chemotherapy. Conclusions: Chronic recurrent fever, lymphadenopathy and hepatosplenomegaly are the most common clinical manifestations in children with EBV(+)LPD. Involvement of lung, central nervous system, intestinal tract, skin and other organs are also involved frequently. For children with chronic fever of unknown cause and accompanied by lymphadenopathy and (or) hepatosplenomegaly, EBV (+) LPD should be considered highly when the whole blood EBV-DNA load continues to increase significantly, early biopsy of the proliferative lesion should be performed to make a definite diagnosis. The prognosis of EBV (+) LPD is poor, and some evolve to lymphoma, hematopoietic stem cell transplantation is an effective way to treat this disease.

Interplay of two functionally and structurally distinct domains of the c-fos AU-rich element specifies its mRNA-destabilizing function.

AU-rich elements (ARE) in the 3' untranslated region of many highly labile mRNAs for proto-oncogenes, lymphokines, and cytokines can act as an RNA-destabilizing element. The absence of a clear understanding of the key sequence and structural features of the ARE that are required for its destabilizing function has precluded the further elucidation of its mode of action and the basis of its specificity. Combining extensive mutagenesis of the c-fos ARE with in vivo analysis of mRNA stability, we were able to identify mutations that exhibited kinetic phenotypes consistent with the biphasic decay characteristic of a two-step mechanism: accelerated poly(A) shortening and subsequent decay of the transcribed portion of the mRNA. These mutations, which affected either an individual step or both steps, all changed the mRNA stability. Our experiments further revealed the existence of two structurally distinct and functionally interdependent domains that constitute the c-fos ARE. Domain I, which is located within the 5' 49-nucleotide segment of the ARE and contains the three AUUUA motifs, can function as an RNA destabilizer by itself. It forms the essential core unit necessary for the ARE-destabilizing function. Domain II is a 20-nucleotide U-rich sequence which is located within the 3' part of the c-fos ARE. Although it alone can not act as an RNA destabilizer, this domain serves two critical roles: (i) its presence enhances the destabilizing ability of domain I by accelerating the deadenylation step, and (ii) it has a novel capacity of buffering decay-impeding effects exerted by mutations introduced within domain I. A model is proposed to explain how these critical structural features may be involved in the c-fos ARE-directed mRNA decay pathway. These findings have important implications for furthering our understanding of the molecular basis of differential mRNA decay mediated by different AREs.

Thymidylate synthase protein and p53 mRNA form an in vivo ribonucleoprotein complex.

A thymidylate synthase (TS)-ribonucleoprotein (RNP) complex composed of TS protein and the mRNA of the tumor suppressor gene p53 was isolated from cultured human colon cancer cells. RNA gel shift assays confirmed a specific interaction between TS protein and the protein-coding region of p53 mRNA, and in vitro translation studies demonstrated that this interaction resulted in the specific repression of p53 mRNA translation. To demonstrate the potential biological role of the TS protein-p53 mRNA interaction, Western immunoblot analysis revealed nearly undetectable levels of p53 protein in TS-overexpressing human colon cancer H630-R10 and rat hepatoma H35(F/F) cell lines compared to the levels in their respective parent H630 and H35 cell lines. Polysome analysis revealed that the p53 mRNA was associated with higher-molecular-weight polysomes in H35 cells compared to H35(F/F) cells. While the level of p53 mRNA expression was identical in parent and TS-overexpressing cell lines, the level of p53 RNA bound to TS in the form of RNP complexes was significantly higher in TS-overexpressing cells. The effect of TS on p53 expression was also investigated with human colon cancer RKO cells by use of a tetracycline-inducible system. Treatment of RKO cells with a tetracycline derivative, doxycycline, resulted in 15-fold-induced expression of TS protein and nearly complete suppression of p53 protein expression. However, p53 mRNA levels were identical in transfected RKO cells in the absence and presence of doxycycline. Taken together, these findings suggest that TS regulates the expression of p53 at the translational level. This study identifies a novel pathway for regulating p53 gene expression and expands current understanding of the potential role of TS as a regulator of cellular gene expression.

WSe2 few layers with enzyme mimic activity for high-sensitive and high-selective visual detection of glucose.

As one of the transition metal dichalcogenide materials, WSe2 in the form of a few layers (nanosheets) have received much attention due to their unique physical, optical and electrical properties. Herein, we demonstrate that WSe2 nanosheets possess intrinsic enzyme mimic activity. Under acidic conditions, they exhibit pronounced peroxidase-like property. The Michaelis-Menten kinetics indicate that the catalytic activity of WSe2 nanosheets is comparable to that of horseradish peroxidase. Based on the color reaction, a platform of WSe2 nanosheets was constructed to detect glucose concentration and it showed high sensitivity and high selectivity, which means that WSe2 nanosheets with peroxidase-like property can be used to develop a highly sensitive and selective colorimetric method for glucose detection. Moreover, due to the electron-transferring and antioxidant properties of WSe2 few layers, the peroxidase-like catalysis is proposed. These findings pave the way for further application of WSe2 nanosheets in nano-biomedicine.

Nanodiamonds as pH-switchable oxidation and reduction catalysts with enzyme-like activities for immunoassay and antioxidant applications.

Nanodiamonds (NDs) have recently become a focus of interest from the viewpoints of both science and technology. Their intriguing properties make them suitable as biologically active substrates, in biosensor applications as well as diagnostic and therapeutic biomedical imaging probes. Here, we demonstrate that NDs, as oxidation and reduction catalysts, possess intrinsic enzyme mimetic properties of oxidase, peroxidase and catalase, and these behaviors can be switched by modulating the pH value. NDs not only catalyze the reduction of oxygen (O2) and hydrogen peroxide (H2O2) at acidic pH, but also catalyze the dismutation decomposition of H2O2 to produce O2 at alkaline pH. It was proposed that the molecular mechanism of their peroxidase-like activity is electron-transfer acceleration, the source of which is likely derived from oxygen containing functional groups on their surface. Based on the color reaction, a nanodiamond-based enzyme linked immunosorbent assay (ELISA) was established for the detection of immunoglobulin G (IgG). Surprisingly, NDs display an excellent antioxidant activity due to the protective effect against H2O2-induced cellular oxidative damage. These findings make NDs a promising enzyme mimetic candidate and expand their applications in biocatalysis, bioassays and nano-biomedicine.

NMR-based metabolomics for the environmental assessment of Kaohsiung Harbor sediments exemplified by a marine amphipod (Hyalella azteca).

Inflow of wastewater from upstream causes a large flux of pollutants to enter Kaohsiung Harbor in Taiwan daily. To reveal the ecological risk posed by Kaohsiung Harbor sediments, an ecological metabolomic approach was employed to investigate environmental factors pertinent to the physiological regulation of the marine amphipod Hyalella azteca. The amphipods were exposed to sediments collected from different stream inlets of the Love River (LR), Canon River (CR), Jen-Gen River (JR), and Salt River (SR). Harbor entrance 1 (E1) was selected as a reference site. After 10-day exposure, metabolomic analysis of the Hyalella azteca revealed differences between two groups: {E1, LR, CR} and {JR, SR}. The metabolic pathways identified in the two groups of amphipods were significantly different. The results demonstrated that NMR-based metabolomics can be effectively used to characterize metabolic response related to sediment from polluted areas.