248 research outputs found
Analysis of the Properties of Adjoint Equations and Accuracy Verification of Adjoint Model Based on FVM
There are two different approaches on how to formulate adjoint numerical model (ANM). Aiming at the disputes arising from the construction methods of ANM, the differences between nonlinear shallow water equation and its adjoint equation are analyzed; the hyperbolicity and homogeneity of the adjoint equation are discussed. Then, based on unstructured meshes and finite volume method, a new adjoint model was advanced by getting numerical model of the adjoint equations directly. Using a gradient check, the correctness of the adjoint model was verified. The results of twin experiments to invert the bottom friction coefficient (Manning’s roughness coefficient) indicate that the adjoint model can extract the observation information and produce good quality inversion. The reason of disputes about construction methods of ANM is also discussed in the paper
Prevalence of hyperglycemia among adults with newly diagnosed HIV/AIDS in China
BACKGROUND: The prevalence of hyperglycemia among HIV-infected persons who are not receiving antiretroviral therapy is unknown. We conducted a cross-sectional survey to estimate the prevalence of hyperglycemia among Chinese adults with newly diagnosed HIV/AIDS. METHODS: Two thousand and six newly diagnosed HIV/AIDS patients from 10 provinces and municipalities in China were selected during 2009 to 2010. After an overnight fast, serum samples were collected to measure glucose concentrations. Demographics and medical histories were recorded. Factors associated with the presence of diabetes were analysed by logistic regression. RESULTS: Among the 2006 patients, 75.67% were male. Median age was 40 years (range: 18–86 years). 19.99% had hyperglycemia, 9.47% had impaired fasting glucose (IFG) and 10.52% had diabetes. The prevalences of hyperglycemia, of IFG and of diabetes were 21.54%, 10.28% and 11.27% among men and 15.16%, 6.97% and 8.20% among women, respectively. The prevalence of diabetes increased with increasing age (7.00%, 13.36% and 21.21% among patients who were 18–40, 40–60, and ≥60 years of age respectively) and with decreasing CD4 count (6.74%, 8.45%, 9.69%, and 12.66% among patients with CD4 count of ≥350, 200–350, 50–200, and < 50/mm(3) respectively). The prevalence of diabetes was higher among ethnic minority patients than among the Han patients (14.37% versus 9.24%). The logistic analysis showed that older age, lower CD4 count and minority ethnicity were significantly associated with an increased risk of diabetes. CONCLUSIONS: Hyperglycemia is highly prevalent among Chinese adults with newly diagnosed HIV/AIDS. Older age, lower CD4 count and minority ethnicity are associated with increased risk of diabetes. All newly diagnosed HIV/AIDS individuals should be routinely evaluated for hyperglycemia
Stimulation of trans-resveratrol biosynthesis in Vitis vinifera cv. Kyoho cell suspension cultures by 2, 3-dihydroxypropyl jasmonate elicitation
Background: Plant cell suspension culture of Vitis vinifera is a
promising technology for investigating different factors that are able
to induce and/or modify stilbenes biosynthesis. Jasmonates have been
reported to play an important role in a signal transduction pathway
that regulates defence responses as well as the production of secondary
metabolites. In this study, 2, 3-dihydroxypropyl jasmonate (DHPJA) was
used to investigate its effect on stimulating trans-resveratrol (t-R)
accumulation and the plant defence responses in Vitis vinifera cv.
Kyoho cell suspension cultures for the first time. Results: It
demonstrated that DHPJA had superior effects on stilbenoids
accumulation over methyl jasmonate (MeJA). The optimal condition was
150 \u3bcM DHPJA added on day 15 of cultivation period, with the
highest level of t-R accumulation which was increased 1.8-fold and
1.3-fold compared with the control and 150 \u3bcM MeJA respectively.
DHPJA induced stronger plant defence responses, including oxidative
burst and activation of L-phenylalanine ammonia lyase (PAL) than MeJA.
H2O2 generation induced by DHPJA played a significant role in enhancing
t-R accumulation. Adding a specific inhibitor of H2O2 signalling
pathway inhibited DHPJA-induced t-R accumulation, but had no effects on
DHPJA-induced other metabolites accumulation, which resulted in
regulations of product diversity. Conclusions: This study demonstrated
that DHPJA was an efficient elicitor to enhance t-R accumulation by
activating stronger oxidative burst, and H2O2 signalling pathway could
regulate product diversity in DHPJA-induced V. vinifera cv. Kyoho cell
suspension cultures
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COVID-19 infection: the China and Italy perspectives.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Since its first report in December 2019, despite great efforts made in almost every country worldwide, this disease continues to spread globally, especially in most parts of Europe, Iran, and the United States. Here, we update the recent understanding in clinical characteristics, diagnosis strategies, as well as clinical management of COVID-19 in China as compared to Italy, with the purpose to integrate the China experience with the global efforts to outline references for prevention, basic research, treatment as well as final control of the disease. Being the first two countries we feel appropriate to evaluate the evolution of the disease as well as the early result of the treatment, in order to offer a different baseline to other countries. It is also interesting to compare two countries, with a very significant difference in population, where the morbidity and mortality has been so different, and unrelated to the size of the country
Symmetry-protected higher-order exceptional points in staggered flatband rhombic lattices
Higher-order exceptional points (EPs), which appear as multifold degeneracies
in the spectra of non-Hermitian systems, are garnering extensive attention in
various multidisciplinary fields. However, constructing higher-order EPs still
remains as a challenge due to the strict requirement of the system symmetries.
Here we demonstrate that higher-order EPs can be judiciously fabricated in PT
-symmetric staggered rhombic lattices by introducing not only on-site gain/loss
but also nonHermitian couplings. Zero-energy flatbands persist and
symmetry-protected third-order EPs (EP3) arise in these systems owing to the
non-Hermitian chiral/sublattice symmetry, but distinct phase transitions and
propagation dynamics occur. Specifically, the EP3 arises at the Brillouin zone
(BZ) boundary in the presence of on-site gain/loss. The single-site excitations
display an exponential power increase in the PT -broken phase. Meanwhile, a
nearly flatband sustains when a small lattice perturbation is applied. For the
lattices with non-Hermitian couplings, however, the EP3 appears at the BZ
center. Quite remarkably, our analysis unveils a dynamical
delocalization-localization transition for the excitation of the dispersive
bands and a quartic power increase beyond the EP3. Our scheme provides a new
platform towards the investigation of the higher-order EPs, and can be further
extended to the study of topological phase transitions or nonlinear processes
associated with higher-order EPs.Comment: 10 pages, 10 figure
Interferon-Gamma Release Assays for the Diagnosis of Active Tuberculosis in HIV-Infected Patients: A Systematic Review and Meta-Analysis
BACKGROUND: Interferon-gamma release assays (IGRAs) have provided a new method for the diagnosis of Mycobacterium tuberculosis infection. However, the role of IGRAs for the diagnosis of active tuberculosis (TB), especially in HIV-infected patients remains unclear. METHODS: We searched PubMed, EMBASE and Cochrane databases to identify studies published in January 2001-July 2011 that evaluated the evidence of using QuantiFERON-TB Gold in-tube (QFT-GIT) and T-SPOT.TB (T-SPOT) on blood for the diagnosis of active TB in HIV-infected patients. RESULTS: The search identified 16 eligible studies that included 2801 HIV-infected individuals (637 culture confirmed TB cases). The pooled sensitivity for the diagnosis of active TB was 76.7% (95%CI, 71.6-80.5%) and 77.4% (95%CI, 71.4-82.6%) for QFT-GIT and T-SPOT, respectively, while the specificity was 76.1% (95%CI, 74.0-78.0%) and 63.1% (95%CI, 57.6-68.3%) after excluding the indeterminate results. Studies conducted in low/middle income countries showed slightly lower sensitivity and specificity when compared to that in high-income countries. The proportion of indeterminate results was as high as 10% (95%CI, 8.8-11.3%) and 13.2% (95%CI, 10.6-16.0%) for QFT-GIT and T-SPOT, respectively. CONCLUSION: IGRAs in their current formulations have limited accuracy in diagnosing active TB in HIV-infected patients, and should not be used alone to rule out or rule in active TB cases in HIV-infected patients. Further modification is needed to improve their accuracy
Association Between a Type 2 Inflammatory Disease Burden Score and Outcomes Among Patients with Asthma
Funding This study was sponsored by Sanofi and Regeneron Pharmaceuticals, Inc. Acknowledgments At the time of development of this manuscript, Fen Ye was an employee of Sanofi and Yufang Lu was an employee of Regeneron Pharmaceuticals.Medical writing support was provided by Abby Armitt, MSc, and Gauri Saal, MA Economics, of Prime, Knutsford, UK, and funded by Sanofi and Regeneron Pharmaceuticals, Inc.Peer reviewedPublisher PD
Low Serum Magnesium Level Is Associated with Microalbuminuria in Chinese Diabetic Patients
Whether serum magnesium deficiency is independently associated with the prevalence of microalbuminuria is still unclear. The objective of the present study was to elucidate the association between serum magnesium and microalbuminuria in diabetic patients. A cross-sectional study was conducted in 1829 diabetic subjects (aged ≥ 40 years) from Shanghai, China. Subjects were divided into three groups according to serum magnesium tertiles. A first-voided early-morning spot urine sample was obtained for urinary albumin-creatinine ratio (UACR) measurement. Microalbuminuria was defined as 30 mg/g ≤ UACR < 300 mg/g. Overall, 208 (11.37%) of the study population had microalbuminuria, with similar proportions in both genders (). The prevalence of microalbuminuria in tertile 1 of serum magnesium was higher than the prevalence in tertile 2 and tertile 3 (15.98%, 9.72%, and 8.46%, resp.; for trend <0.0001). After adjustment for age, sex, BMI, blood pressure, lipidaemic profile, HbA1c, eGFR, history of cardiovascular disease, HOMA-IR, antihypertensive and antidiabetic medication, and diabetes duration, we found that, compared with the subjects in tertile 3 of serum magnesium, those in tertile 1 had 1.85 times more likeliness to have microalbuminuria. We concluded that low serum magnesium level was significantly associated with the prevalence of microalbuminuria in middle-aged and elderly Chinese
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