Review: Groundwater recharge estimation in northern China karst regions

Reliable estimates of groundwater recharge are crucial for the groundwater resources evaluating and sustainable utilization plans formulating. To protect the precious karst groundwater resources, this paper critically reviewed the previous studies on karst groundwater recharge in northern China karst regions from the perspective of diffuse recharge and focused recharge, and took Niangziguan Spring catchment as a case study. It is concluded that for the 119 karst groundwater systems, 52% occur diffuse recharge through precipitation infiltration, 48% occur both diffuse recharge through precipitation infiltration and focused recharge through surface water leakage. The mean annual precipitation, diffuse recharge and infiltration coefficient (IC, as percentage of precipitation) are 560 mm, 136 mm and 23.1%, respectively. A high correlation was observed between annual precipitation and annual diffuse recharge with a nonlinear relationship. The IC can vary substantially even with the same annual precipitation between 9.3 and 38.0%, with an evidently increasing trend eastward. This reflects a significant difference in the degree of karstification for the northern karst regions. The most commonly applied for recharge assessment in northern China karst regions is equal volume spring flow method, the chloride mass balance method is highly recommended for groundwater recharge estimation of the regions based on the case study. This work provides reference for recharge estimation, assessment and management of karst groundwater resources in northern China

New Travelling-Wave Solutions for Dodd-Bullough Equation

A new method, which assumes ϕ' with a function form of f(eϕ), is applied to solve the Dodd-Bullough equation ϕuv=eϕ-e-2ϕ through travelling-wave transformation. A new family of explicit travelling wave solutions is derived. The proposed method works efficiently to be applied to solve other forms of Dodd-Bullough equations

Pharmacokinetics and bioequivalence evaluation of acamprosate calcium tablets in healthy Chinese volunteers

AbstractBackgroundFew pharmacokinetic data of acamprosate were available in Chinese population and no medication is approved for alcohol dependence in China.Purpose1. Investigate the pharmacokinetic properties of acamprosate calcium in healthy Chinese male volunteers on single- and multiple-dose administration. 2. Compare the bioequivalence of two formulations of acamprosate calcium tablets both under fasting and fed conditions.MethodsThis open-label, randomized study included 3 stages. In each stage, a 2-way crossover bioequivalence study was conducted to study the pharmacokinetic properties and bioequivalence of acamprosate calcium tablets on multiple dosing after standardized meals, single dosing under fasting conditions and fed conditions, respectively. The washout period between each treatment in a stage and between each stage was 1week. Plasma acamprosate calcium was quantified by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Tolerability was evaluated by monitoring adverse events, physical examinations, 12-lead ECG, and laboratory tests.ResultsTotally, 36 male subjects were enrolled in the study and all of them completed the whole 3 study stages. Main pharmacokinetic parameters of test and reference formulations were as follows: multiple dosing, Tmax 9.94±6.59 and 9.47±5.47h, Cmax 435.74±348.10 and 346.54±155.66ng·mL−1, AUC0-t 8600.52±5264.77 and 9315.10±6820.03ng·mL−1·h, AUC0–∞ 8845.38±5838.18 and 9669.24±7326.53ng·mL−1·h, t1/2 10.06±8.83 and 9.87±10.35h; single dosing under fasting conditions, Tmax 7.29±4.87 and 6.57±1.85h, Cmax 247.85±110.05 and 244.64±132.43ng·mL−1, AUC0-t 3385.41±1418.92 and 3496.24±1767.29ng·mL−1·h, AUC0–∞ 3781.53±1556.96 and 3829.56±1981.25ng·mL−1·h, t1/2 13.07±17.24 and 10.26±7.78h; single dosing under fed conditions, Tmax 17.72±9.42 and 19.50±9.84h, Cmax 183.90±74.52 and 168.14±60.67ng·mL−1, AUC0-t 3181.71±1368.24 and 3575.11±1416.39ng·mL−1·h, AUC0–∞3442.39±2002.53 and 3624.44±1418.12ng·mL−1·h, t1/2 8.76±12.28 and 6.67±4.84h, respectively. In all three stages, 90% CIs for the test/reference ratio of AUC0–t and AUC0–∞ were located within 80%–125%, 90% CI for Cmax was within 70%–143%.ConclusionsSimilar pharmacokinetic results of acamprosate calcium tablets in healthy Chinese volunteers were found as those in Caucasic population. In all three stages, the two formulations met the regulatory criteria for bioequivalence.Chictr.org identifier: ChiCTR-TTRCC-14004853

Achieving low energy consuming bio-based piezoelectric nanogenerators via modulating the inner layer thickness for a highly sensitive pedometer

Considering their drawbacks of environmental pollution, biodegradable cellulose-based materials are becoming one of the most promising alternative candidates for conventional petroleum-based polymers, which are considered the fundamental materials for dynamical units in human-machine interaction systems. Using an up-to-date hydrogen bond replacement strategy, which means using the highly electronegative F− in polyvinylidene fluoride (PVDF) to replace the intramolecular hydrogen bonds in cellulose for weakening the self-assembly behavior, herein, multilayer-structured piezoelectric nanogenerators (PENGs) composed of cellulose, a small amount of PVDF, and Ba0.7Ca0.3Zr0.2Ti0.8O3 (BCZT) fillers were fabricated via modified tape-casting technology. Due to the hydrogen bond network, which was confirmed using multiple characterization methods, the fillers dispersed uniformly in the matrix. Through changing the inner layer thickness, the output performance of the PENGs can be subtly modulated, which is revealed to be caused by the synergistic effect between the trapped electrons and the inter-squeezing between adjacent particles by employing the band theory. When applied to a pedometer, one of the essential devices for monitoring human health, such a modulation can significantly improve its sensitivity. The water contact angle test also indicates their potential for use in humid environments. Compared with some typical cellulose-based PENGs, our device shows outstanding performance in PD/F, defined as the power density triggered by unit force, indicating our PENG's low energy consumption characteristic.</p

A dataset of low-carbon energy transition index for Chinese cities 2003–2019

Cities are at the heart of climate change mitigation as they account for over 70% of global carbon emissions. However, cities vary in their energy systems and socioeconomic capacities to transition to renewable energy. To address this heterogeneity, this study proposes an Energy Transition Index (ETI) specifically designed for cities, and applies it to track the progress of energy transition in Chinese cities. The city-level ETI framework is based on the national ETI developed by the World Economic Forum (WEF) and comprises two sub-indexes: the Energy System Performance sub-index, which evaluates the current status of cities’ energy systems in terms of energy transition, and the Transition Readiness sub-index, which assesses their socioeconomic capacity for future energy transition. The initial version of the dataset includes ETI and its sub-indexes for 282 Chinese cities from 2003 to 2019, with annual updates planned. The spatiotemporal data provided by the dataset facilitates research into the energy transition roadmap for different cities, which can help China achieve its energy transition goals

Developing the host for targeted integration cell line development

Unlike the conventional random integration (RI) cell line development (CLD), the targeted integration (TI) CLD introduces the transgene at a predetermined “hot-spot” in the CHO genome with a defined copy number (1-2 copies). Given the low copy number and the pretested integration site, TI cell lines likely exhibit better stability compared to RI cell lines. In this study, we performed a genome wide screening using transposon based cassette integration and established a TI host (255-3) that has a single landing cassette inserted in its genome. Host 255-3 was able to support the CLD for three test molecules with product titers similar to those of the corresponding RI cell lines. For two regular antibody test cases, the top four TI cell lines achieved ~4-5g/L. For a proven difficult to express antibody, the top four TI lines achieved ~1-1.2g/L. The product titer for this hard to express molecule was increased 3-fold with additional vector improvement. Moreover, the timeline for CLD was shortened by ~2 weeks and resources required per cell line were substantially reduced using the TI method. Together these data indicate that the TI host we developed can be a suitable host to support our clinical / commercial CLD

Safety and efficacy of ex vivo expanded CD34 stem cells in murine and primate models

Background: Hematopoietic stem cell (HSC) transplantation has been widely applied to the treatment of malignant blood diseases. However, limited number of functional HSCs hinders successful transplantation. The purpose of our current study is to develop a new and cost-efficient medium formulation that could greatly enhance the expansion of HSCs while retaining their long-term repopulation and hematopoietic properties for effective clinical transplantation. Methods: Enriched human CD34(+) cells and mobilized nonhuman primate peripheral blood CD34(+) cells were expanded with a new, cost-efficient expansion medium formulation, named hematopoietic expansion medium (HEM), consisting of various cytokines and nutritional supplements. The long-term repopulation potential and hematologic-lineage differentiation ability of expanded human cells were studied in the non-obese diabetic/severe combined immunodeficiency mouse model. Furthermore, the efficacy and safety studies were performed by autologous transplantation of expanded primate cells in the nonhuman primate model. Results: HEM could effectively expand human CD34(+) cells by up to 129 fold within 9 days. Expanded HSCs retained long-term repopulation potential and hematologic-lineage differentiation ability, as indicated by (1) maintenance (over unexpanded HSCs) of immunophenotypes of CD38(-)CD90(+)CD45RA(-)CD49f(+) in CD34(+) cells after expansion; (2) significant presence of multiple human hematopoietic lineages in mouse peripheral blood and bone marrow following primary transplantation; (3) enrichment (over unexpanded HSCs) in SCID-repopulating cell frequency measured by limiting dilution analysis; and (4) preservation of both myeloid and lymphoid potential among human leukocytes from mouse bone marrow in week 24 after primary transplantation or secondary transplantation. Moreover, the results of autologous transplantation in nonhuman primates demonstrated that HEM-expanded CD34(+) cells could enhance hematological recovery after myelo-suppression. All primates transplanted with the expanded autologous CD34(+) cells survived for over 18 months without any noticeable abnormalities. Conclusions: Together, these findings demonstrate promising potential for the utility of HEM to improve expansion of HSCs for clinical application.State Scientific Key Projects for New Drug Research and Development [2011ZX09102-010-04, 2011ZX09401-027]; International Cooperation and Exchange Program, China [2013DFA30830]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

An Improved Empirical Fuel Cell Polarization Curve Model Based on Review Analysis

Based on a review analysis of empirical fuel cell polarization curve models in the literature, an improved model that can predict fuel cell performance with only measured current-voltage data is developed. The fitting characteristics of this new model are validated by fitting bench test data and road test data. In the case of bench test data, a comparison of the new model and two representative models is conducted, and the results show that the new model presents the best fitting effects over a whole range of current densities. Moreover, the fitted ohmic resistances derived from the new model show good agreement with the measured values obtained through a current interruption test. In the case of using road test data, the new model also presents excellent fitting characteristics and convenience for application. It is the author’s belief that the new model is beneficial for the application-oriented research of fuel cells due to its prominent features, such as conciseness, flexibility, and high accuracy

A Thymidine Kinase recombinant protein-based ELISA for detecting antibodies to Duck Plague Virus

<p>Abstract</p> <p>Background</p> <p>Duck plague virus (DPV) is the causative agent of Duck Plague (DP) that causes significant morbidity and mortality throughout duck-producing areas of the world. The diagnosis of DP currently relies on the use of live or inactivated whole DPV virion as antigens in ELISA, but it is too laborious and expensive for routine application, and it is still difficult to get purified DPV virion with current technology.</p> <p>Results</p> <p>In this study, we describe the expression and purification of a recombinant Thymidine Kinase (TK) protein which makes antigen in an in-house developed, optimized and standardized ELISA. The specificity of the optimized TK-ELISA was evaluated by antisera against Duck Plague Virus (DPV), Duck Hepatitis B Virus (DHBV), Duck Hepatitis Virus (DHV), <it>Riemerella Anatipestifer</it>(<it>R. A</it>), <it>Escherichia coli </it>(<it>E. coli</it>) and <it>Salmonella anatum </it>(<it>S. anatum</it>). Only antisera against DPV yielded a specific and strong signal. In order to determine the sensitivity of the TK-ELISA, a panel of diluted sera was tested, and the minimum detection limit of 1:2560 (OD450 nm = 0.401) was obtained according to the endpoint cut-off (0.2438). The repeatability and reproducibility under the experimental conditions demonstrates a low variability (P > 0.05). The suspected sera samples (n = 30) were determined by TK-ELISA and the positive rate is 90% (27/30), and the TK-ELISA showed 83.33% (22+3/30) coincidence rate with the Serum Neutralization Test (SNT) and 90% (24+3/30) coincidence rate with the whole DPV virion based-ELISA (DPV-ELISA). When defining the dynamics of antibody response to attenuated live DPV vaccine, the maximum antibodies is reached after 4 weeks.</p> <p>Conclusions</p> <p>The results suggest that the TK-ELISA provides high specificity, sensitivity, repeatability and reproducibility for detection of anti-DPV antibodies in duck sera, and has the potential to be much simpler than DPV-ELISA and SNT for the sera epidemiological investigation.</p

Sulforaphane Inhibits Foam Cell Formation and Atherosclerosis via Mechanisms Involving the Modulation of Macrophage Cholesterol Transport and the Related Phenotype

Sulforaphane (SFN), an isothiocyanate, is one of the major dietary phytochemicals found in cruciferous vegetables. Many studies suggest that SFN can protect against cancer and cardiometabolic diseases. Despite the proposed systemic and local vascular protective mecha-nisms, SFN’s potential to inhibit atherogenesis by targeting macrophages remains unknown. In this study, in high-fat-diet-fed ApoE-deficient (ApoE-/-) mice, oral SFN treatment improved dyslipidemia and inhibited atherosclerotic plaque formation and the unstable phenotype, as demonstrated by reductions in the lesion areas in both the aortic sinus and whole aorta, per-centages of necrotic cores, vascular macrophage infiltration and reactive oxygen species (ROS) generation. In THP-1-derived macrophages, SFN pre-administration alleviated oxidized low-density lipoprotein (ox-LDL)-induced lipid accumulation, oxidative stress and mitochondrial injury. Moreover, a functional study revealed that peritoneal macrophages isolated from SFN-treated mice exhibited attenuated cholesterol influx and enhanced apolipoprotein A-I (apoA-I)- and high-density lipoprotein (HDL)-mediated cholesterol efflux. Mechanistic analysis revealed that SFN supplementation induced both intralesional and intraperitoneal macrophage phenotypic switching toward high expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and ATP binding cassette subfamily A/G member 1 (ABCA1/G1) and low expression of peroxisome proliferator-activated receptor γ (PPARγ) and cluster of differen-tiation 36 (CD36), which was further validated by the aortic protein expression. These results suggest that the regulation of macrophages cholesterol transport and accumulation may be mainly responsible for SFN's potential atheroprotective properties, and the regulatory mecha-nisms might involve upregulating ABCA1/G1 and downregulating CD36 via the modulation of PPARγ and Nrf2