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1.
Eur J Pharmacol ; : 176862, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39068974

RESUMO

We and other groups have documented that bone marrow-mesenchymal stem cells (BM-MSCs) from Systemic lupus erythematosus (SLE) patients demonstrated signs of senescence, including reduced ability of regulating Treg. Treg cell defects or Treg cell deficiency are regarded as significant factors in the progression of SLE. Exosomes, nanoscale vesicles, abound in molecular and genetic contents, play a critical role in intercellular communications. The purpose of this research is to investigate the mechanism of MSCs-exosomes regulating Tregs cells in SLE, further elucidate the mechanism of immune dysregulation of aging BM-MSCs, and provide theoretical basis and data support for new targets of SLE treatment. In the study, BM-MSCs and exosomes were isolated successfully. Exosomes could be up-taken by naïve CD4+T cells. MSCs-exosomes attenuated SLE clinical manifestation in vivo, but MSCs-exosomes from SLE patients were ineffective. MSCs-exosomes from SLE patients dysregulated Treg cells differentiation in vivo and in vitro. Exosomal miR-20a-5p contributed to the effect of MSCs-exosomes regulating Treg cells. Up-regulating the expression of miR-20a-5p in SLE MSCs-exosomes can restore their ability to promote Treg differentiation and treatment effect. This study further elucidated the role of in the immunomodulatory mechanism of BM-MSCs-exosomes and provided new ideas for the non-cellular autologous transplantation therapy of SLE.

2.
Sci Rep ; 14(1): 15293, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961118

RESUMO

To solve the problems of poor top coal drawing, lagging collapse, and difficulty in parallel operation of mining and drawing in extra-thick coal seams, considering the 8222 working face of the Tashan Mine as the engineering background, we first investigate the basic problems of fully mechanized top coal drawing mining in extra-thick coal seams using the single-round group drawing method (GDM). We then analyze the drawing law of top coal with different thicknesses under the single-round GDM from the aspects of top coal recovery (TCR) and drawing efficiency, coal loss mechanism, and the relation between TCR and gangue content (GC), providing a basis for determining the process parameters of GDM. Results indicate that as the top coal thickness increases, the number of drawing openings considerably influences drawing efficiency and top coal loss. And there is a notable thickness effect of the number of drawing openings on the top coal loss. There is a quantitative relationship among TCR, cumulative GC (CGC) and instantaneous GC (IGC), and CGC and TCR can be predicted based on the IGC. Consequently, theoretical analysis and numerical simulation results indicate that the optimal IGC threshold at the coal drawing openings between 31.2 and 40%. Through optimizing the coal drawing method and strictly controlling the IGC at the coal drawing openings on-site, the measured working face TCR increased from 75.25 to 90.12%, and CGC was controlled at approximately 9%. Meanwhile, the average coordination efficiency of mining and drawing time reaches 68.2%, effectively ensuring the construction of a coal mine with an annual output of 15 million tons.

3.
J Integr Plant Biol ; 66(7): 1295-1312, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38695649

RESUMO

Cultivating high-yield wheat under limited water resources is crucial for sustainable agriculture in semiarid regions. Amid water scarcity, plants activate drought response signaling, yet the delicate balance between drought tolerance and development remains unclear. Through genome-wide association studies and transcriptome profiling, we identified a wheat atypical basic helix-loop-helix (bHLH) transcription factor (TF), TabHLH27-A1, as a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat. TabHLH27-A1/B1/D1 knock-out reduced wheat drought tolerance, yield, and water use efficiency (WUE). TabHLH27-A1 exhibited rapid induction with polyethylene glycol (PEG) treatment, gradually declining over days. It activated stress response genes such as TaCBL8-B1 and TaCPI2-A1 while inhibiting root growth genes like TaSH15-B1 and TaWRKY70-B1 under short-term PEG stimulus. The distinct transcriptional regulation of TabHLH27-A1 involved diverse interacting factors such as TaABI3-D1 and TabZIP62-D1. Natural variations of TabHLH27-A1 influence its transcriptional responses to drought stress, with TabHLH27-A1Hap-II associated with stronger drought tolerance, larger root system, more spikelets, and higher WUE in wheat. Significantly, the excellent TabHLH27-A1Hap-II was selected during the breeding process in China, and introgression of TabHLH27-A1Hap-II allele improved drought tolerance and grain yield, especially under water-limited conditions. Our study highlights TabHLH27-A1's role in balancing root growth and drought tolerance, providing a genetic manipulation locus for enhancing WUE in wheat.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Raízes de Plantas , Triticum , Água , Triticum/genética , Triticum/crescimento & desenvolvimento , Triticum/fisiologia , Triticum/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Água/metabolismo , Locos de Características Quantitativas/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Estresse Fisiológico/genética , Estudo de Associação Genômica Ampla , Resistência à Seca
4.
Front Bioeng Biotechnol ; 12: 1310464, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38444649

RESUMO

The utilization of compression garments (CGs) has demonstrated the potential to improve athletic performance; however, the specific mechanisms underlying this enhancement remain a subject of further investigation. This study aimed to examine the impact of CGs on running mechanics and muscle synergies from a neuromuscular control perspective. Twelve adult males ran on a treadmill at 12 km/h, while data pertaining to lower limb kinematics, kinetics, and electromyography were collected under two clothing conditions: whole leg compression garments and control. The Non-negative matrix factorization algorithm was employed to extract muscle synergy during running, subsequently followed by cluster analysis and correlation analysis. The findings revealed that the CGs increased knee extension and reduced hip flexion at foot strike compared with the control condition. Moreover, CGs were found to enhance stance-phase peak knee extension, while diminishing hip flexion and maximal hip extension during the stance-phase, and the ankle kinematics remained unaltered. We extracted and classified six synergies (SYN1-6) during running and found that only five SYNs were observed after wearing CGs. CGs altered the structure of the synergies and changed muscle activation weights and durations. The current study is the first to apply muscle synergy to discuss the effect of CGs on running biomechanics. Our findings provide neuromuscular evidence for the idea of previous studies that CGs alter the coordination of muscle groups, thereby affecting kinematic characteristics during running.

5.
Fa Yi Xue Za Zhi ; 40(1): 64-69, 2024 Feb 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38500463

RESUMO

Biological evidence is relatively common evidence in criminal cases, and it has strong probative power because it carries DNA information for individual identification. At the scene of fire-related cases, the complex thermal environment, the escape of trapped people, the firefighting and rescue operations, and the deliberate destruction of criminal suspects will all affect the biological evidence in the fire scene. Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes, and found that the blood stains, semen stains, bones, etc. are the main biological evidence which can be easily recovered with DNA in fire scenes. In order to analyze the research status and development trend of biological evidence in fire scenes, this paper systematically sorts out the relevant research, mainly including the soot removal technology, appearance method of typical biological evidence, and possibility of identifying other biological evidence. This paper also prospects the next step of research direction, in order to provide reference for the identification of biological evidence and improve the value of biological evidence in fire scenes.


Assuntos
Manchas de Sangue , Líquidos Corporais , Incêndios , Humanos , Sêmen , DNA/genética
6.
Mol Plant ; 17(3): 438-459, 2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38310351

RESUMO

The spike architecture of wheat plays a crucial role in determining grain number, making it a key trait for optimization in wheat breeding programs. In this study, we used a multi-omic approach to analyze the transcriptome and epigenome profiles of the young spike at eight developmental stages, revealing coordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition. We constructed a core transcriptional regulatory network (TRN) that drives wheat spike formation and experimentally validated a multi-layer regulatory module involving TaSPL15, TaAGLG1, and TaFUL2. By integrating the TRN with genome-wide association studies, we identified 227 transcription factors, including 42 with known functions and 185 with unknown functions. Further investigation of 61 novel transcription factors using multiple homozygous mutant lines revealed 36 transcription factors that regulate spike architecture or flowering time, such as TaMYC2-A1, TaMYB30-A1, and TaWRKY37-A1. Of particular interest, TaMYB30-A1, downstream of and repressed by WFZP, was found to regulate fertile spikelet number. Notably, the excellent haplotype of TaMYB30-A1, which contains a C allele at the WFZP binding site, was enriched during wheat breeding improvement in China, leading to improved agronomic traits. Finally, we constructed a free and open access Wheat Spike Multi-Omic Database (http://39.98.48.156:8800/#/). Our study identifies novel and high-confidence regulators and offers an effective strategy for dissecting the genetic basis of wheat spike development, with practical value for wheat breeding.


Assuntos
Estudo de Associação Genômica Ampla , Triticum , Triticum/genética , Melhoramento Vegetal , Redes Reguladoras de Genes/genética , Multiômica , Fatores de Transcrição/genética
7.
Opt Express ; 31(25): 41794-41803, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38087569

RESUMO

The diverse applications of mode-locked fiber lasers (MLFLs) raise various demands on the output of the laser, including the pulse duration, energy, and shape. Simulation is an excellent method to guide the design and construction of an MLFL for on-demand laser output. Traditional simulation of an MLFL uses the split-step Fourier method (SSFM) to solve the nonlinear Schrödinger (NLS) equation, which suffers from high computational complexity. As a result, the inverse design of MLFLs via the traditional SSFM-based simulation method relies on the design experience. Here, a completely data-driven approach for the inverse design of MLFLs is proposed, which significantly reduces the computational complexity and achieves a fast automatic inverse design of MLFLs. We utilize a recurrent neural network to realize fast and accurate MLFL modeling, then the desired cavity settings meeting the output demands are searched via a deep-reinforcement learning algorithm. The results prove that the data-driven method enables the accurate inverse design of an MLFL to produce a preset target femtosecond pulse with a certain duration and pulse energy. In addition, the cavity settings generating soliton molecules with different target separations can also be located via the data-driven inverse design. With the GPU acceleration, the time consumption of the data-driven inverse design of an MLFL is less than 1.3 hours. The proposed data-driven approach is applicable to guide the inverse design of an MLFL to meet the different demands of various applications.

8.
Plant Commun ; 4(4): 100593, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-36945776

RESUMO

A better understanding of wheat functional genomics can improve targeted breeding for better agronomic traits and environmental adaptation. However, the lack of gene-indexed mutants and the low transformation efficiency of wheat limit in-depth gene functional studies and genetic manipulation for breeding. In this study, we created a library for KN9204, a popular wheat variety in northern China, with a reference genome, transcriptome, and epigenome of different tissues, using ethyl methyl sulfonate (EMS) mutagenesis. This library contains a vast developmental diversity of critical tissues and transition stages. Exome capture sequencing of 2090 mutant lines using KN9204 genome-designed probes revealed that 98.79% of coding genes had mutations, and each line had an average of 1383 EMS-type SNPs. We identified new allelic variations for crucial agronomic trait-related genes such as Rht-D1, Q, TaTB1, and WFZP. We tested 100 lines with severe mutations in 80 NAC transcription factors (TFs) under drought and salinity stress and identified 13 lines with altered sensitivity. Further analysis of three lines using transcriptome and chromatin accessibility data revealed hundreds of direct NAC targets with altered transcription patterns under salt or drought stress, including SNAC1, DREB2B, CML16, and ZFP182, factors known to respond to abiotic stress. Thus, we have generated and indexed a KN9204 EMS mutant library that can facilitate functional genomics research and offer resources for genetic manipulation of wheat.


Assuntos
Genômica , Triticum , Triticum/genética , Mutação , Mutagênese , Fenótipo
9.
Colloids Surf B Biointerfaces ; 222: 113109, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36599185

RESUMO

There is an urgent demand for non-invasive and high compliance delivery systems of macromolecules for long-term therapy. However, oral administration of macromolecules is hindered by low permeability and instability in the gastrointestinal (GI) tract. Therefore, we developed a novel aptamer-modified liposomes (Apt-Lip) with M cell targeting for oral delivery of exenatide (EXT). Firstly, we optimized aptamers to M cells by Cell-SELEX and aptamer truncations. The selected aptamer T-M3 (Apt-T-M3) with high binding affinity (Kd = 176 ± 108 nM) and specificity was modified on the surface of liposomes for targeting M cells. Liposomes were formulated by microfluidics system and characterized in terms of morphology, hydrodynamic diameter, zeta potential, and the efficiency of encapsulation. In comparison with non-targeting liposomes, cell uptake in M cells was significantly enhanced by Apt-Lip. Similarly, the transport efficiency of EXT was 2-fold increase using Apt-Lip in M cells. Additionally, the transepithelial electrical resistance (TEER) of M cell monolayers is significantly reduced. In ex vivo intestinal absorption study, Apt-Lip was proved to possess significantly high intestinal absorption in Peyer's patches (PPs) and M cells-specific targeting capacity. Consequently, Apt-Lip promoted the EXT transport could base not only on M cell mediated transport, but also on enhancement of paracellular permeability. In conclusion, the present study supported Apt-Lip as a promising M cell targeted delivery system for oral delivery of macromolecules.


Assuntos
Aptâmeros de Nucleotídeos , Lipossomos , Sistemas de Liberação de Medicamentos , Células M , Substâncias Macromoleculares , Linhagem Celular Tumoral
10.
J Neuroeng Rehabil ; 19(1): 98, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104787

RESUMO

OBJECTIVE: This study aimed to examine the effects of combining transcranial direct current stimulation (tDCS) and foot core exercise (FCE) on the sensorimotor function of the foot (i.e., toe flexor strength and passive ankle kinesthesia) and static balance. METHODS: In this double-blinded and randomized study, 30 participants were randomly assigned into two groups: tDCS combined with FCE and sham combined with FCE (i.e., control group). The participants received 2 mA stimulation for 20 min concurrently with FCE over 4 weeks (i.e., three sessions per week). After the first two groups completed the intervention, a reference group (FCE-only group) was included to further explore the placebo effects of sham by comparing it with the control group. Foot muscle strength, passive ankle kinesthesia, and static balance were assessed at baseline and after the intervention. RESULTS: Compared with the control group and baseline, tDCS combined with FCE could increase toe flexor strength (p < 0.001) and decrease the passive kinesthesia threshold of ankle eversion (p = 0.002). No significant differences in static balance were observed between tDCS + FCE and control groups. The linear regression models showed an association towards significance between the percent changes in metatarsophalangeal joint flexor strength and the anteroposterior average sway velocity of the center of gravity in one-leg standing with eyes closed following tDCS + FCE (r2 = 0.286; p = 0.057). The exploratory analysis also showed that compared with FCE alone, the sham stimulation did not induce any placebo effects during FCE. CONCLUSION: Participating in 4 weeks of intervention using tDCS in combination with FCE effectively enhances toe flexor strength and foot-ankle sensory function.


Assuntos
Terapia por Exercício , Equilíbrio Postural , Estimulação Transcraniana por Corrente Contínua , Humanos , Extremidade Inferior , Equilíbrio Postural/fisiologia
11.
EMBO Rep ; 23(11): e54507, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36148511

RESUMO

A central principle of synaptic transmission is that action potential-induced presynaptic neurotransmitter release occurs exclusively via Ca2+ -dependent secretion (CDS). The discovery and mechanistic investigations of Ca2+ -independent but voltage-dependent secretion (CiVDS) have demonstrated that the action potential per se is sufficient to trigger neurotransmission in the somata of primary sensory and sympathetic neurons in mammals. One key question remains, however, whether CiVDS contributes to central synaptic transmission. Here, we report, in the central transmission from presynaptic (dorsal root ganglion) to postsynaptic (spinal dorsal horn) neurons in vitro, (i) excitatory postsynaptic currents (EPSCs) are mediated by glutamate transmission through both CiVDS (up to 87%) and CDS; (ii) CiVDS-mediated EPSCs are independent of extracellular and intracellular Ca2+ ; (iii) CiVDS is faster than CDS in vesicle recycling with much less short-term depression; (iv) the fusion machinery of CiVDS includes Cav2.2 (voltage sensor) and SNARE (fusion pore). Together, an essential component of activity-induced EPSCs is mediated by CiVDS in a central synapse.


Assuntos
Gânglios Espinais , Células do Corno Posterior , Animais , Células do Corno Posterior/fisiologia , Transmissão Sináptica/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Sinapses , Mamíferos
12.
Cell Rep ; 40(7): 111199, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35977516

RESUMO

The norepinephrine neurons in locus coeruleus (LC-NE neurons) are essential for sleep arousal, pain sensation, and cocaine addiction. According to previous studies, cocaine increases NE overflow (the profile of extracellular NE level in response to stimulation) by blocking the NE reuptake. NE overflow is determined by NE release via exocytosis and reuptake through NE transporter (NET). However, whether cocaine directly affects vesicular NE release has not been directly tested. By recording quantal NE release from LC-NE neurons, we report that cocaine directly increases the frequency of quantal NE release through regulation of NET and downstream protein kinase C (PKC) signaling, and this facilitation of NE release modulates the activity of LC-NE neurons and cocaine-induced stimulant behavior. Thus, these findings expand the repertoire of mechanisms underlying the effects of cocaine on NE (pro-release and anti-reuptake), demonstrate NET as a release enhancer in LC-NE neurons, and provide potential sites for treatment of cocaine addiction.


Assuntos
Transtornos Relacionados ao Uso de Cocaína , Cocaína , Cocaína/farmacologia , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Humanos , Locus Cerúleo/metabolismo , Neurônios/metabolismo , Norepinefrina/metabolismo , Norepinefrina/farmacologia
13.
Front Physiol ; 11: 970, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32848885

RESUMO

Nowadays, compression garments (CGs) are widely used in winter racing sports, such as speed skating, short-track speed skating, alpine skiing, and cross-country skiing. However, the effect of wearing CGs on athletic performance in these specific sports is still not fully examined. Thus, the aim of this narrative review is to summarize the research and application of CGs in winter racing sports and to discuss how the CGs help athletes improve their performance in an integrative manner (i.e., physiology, aerodynamics, and biomechanics). A total of 18 experimental studies dedicated to CGs in winter racing sports were identified from the peer-review scientific literature. The main findings are as follows. (1) Currently, CG studies have mainly focused on drag reduction, metabolism, muscle function, strength performance, and fatigue recovery. (2) The results of most studies conducted in wind tunnels showed that, for cylindrical structures similar to the human body, clothing with rough surfaces can reduce air drag. Notably, the effect of CGs on drag reduction in real competition has not been fully explored in the literature. (3) Compression can reduce muscle vibrations at high impact and help athletes control the center of pressure movement, a function that is important for alpine skiing. Future studies are needed to improve current understanding of the effects of compression clothing microstructure on drag reduction and their stretching in different parts of the body. Furthermore, the design of experimental protocol must be consistent with those during the competition, thus providing a full discussion on energy metabolism, fatigue, and recovery affected by CGs.

14.
Front Physiol ; 11: 589983, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33488394

RESUMO

Snowsport athletes face a high injury risk both during training and in competitions. Reducing injury incidence is crucial for athletes to achieve breakthroughs. This narrative review aimed to summarize and analyze injury data of elite athletes in snowsports and provide references for injury prevention and health security for these athletes and their coaches. A total of 39 studies that investigated snowsport injury were analyzed in the present study. On the basis of injury data of elite athletes in snowsports events, this narrative review focused on four aspects, namely, injury incidence, severity, location and causes. The findings of this review were as follows. (1) The highest injury incidence was recorded in freestyle skiing, followed by alpine skiing and snowboarding, the majority of which were moderate and severe injuries. (2) The proportion of injury in competitions and during training was similar. However, more injuries occurred in official training during the Winter Olympic Games; by contrast, injury proportion was higher in competitions during World Cup/World Championships. (3) The most commonly and severely injured body parts were the knees (29.9%), head and face (12.1%), shoulders and clavicula (10.5%), and lower back (8.9%). The most common injury types were joint and ligament injury (41.5%), fracture and bone stress (24.4%), concussion (11.1%), and muscle/tendon injury (10.7%). (4) The main causes of snowsport injury were collisions, falls, and non-contact injuries. Snowsport injury was also influenced by the skill level of the athletes, gender, course setup and equipment. Future studies should further explore the influence of event characteristics and intrinsic and extrinsic risk factors on snowsport injury. An injury or trauma reconstruction may be developed to predict athletic injuries and provide effective prevention strategies.

15.
Ground Water ; 57(6): 962-968, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30937895

RESUMO

This paper derives an equivalent of Darcian Theis solution for non-Darcian flow induced by constant rate pumping of a well in a confined aquifer. The derivation, which is valid at later times only, is original. It utilizes Izbash's equation. This introduces an additional parameter to Darcian condition, namely, empirical exponent. The solution is a non-Drcian equivalent of Jacob straight line method for analyzing pumping tests at late times. It can be used to determine aquifer parameters: storativity, analogous hydraulic conductivity, and empirical exponent. However, while the Jacob method requires a minimum of only one pumping test with one observation well, the additional parameter in the present solution means that a minimum of two observation wells in one test or two pumping tests at different rates with one observation well are required. The derived solution is applied to a case study at Plomeur in Brittany, France, and is shown to provide a practical and efficient method for analyzing pumping tests where non-Darcian groundwater flow occurs.


Assuntos
Água Subterrânea , França , Modelos Teóricos , Movimentos da Água , Abastecimento de Água , Poços de Água
16.
J Mol Graph Model ; 86: 170-178, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30368087

RESUMO

Dye-sensitized solar cells (DSSCs) are currently the most widely developed low-cost photovoltaic devices. A series of D-A-π-A metal-free organic dyes based on IQ1 were designed and theoretically characterized by introducing different auxiliary acceptors. The results show that the introduction of auxiliary heterocyclic acceptors could effectively tune the photoelectronic properties. In addition, all designed dyes exhibit better optoelectronic properties than IQ1. In particular, dye PIAQ not only has excellent light harvesting capability over the entire visible region and a portion of the near-infrared region, wider light harvesting efficiency (LHE) curve and larger maximum short-circuit current density (JSCmax), but also has narrower energy gap (HOMO-LUMO), larger shift of the conduction band energy level (ΔECB) and lower injection and regeneration driving force. Therefore, the designed sensitizers might have outstanding properties and could be promising candidates for improving DSSCs performance.


Assuntos
Corantes/química , Modelos Teóricos , Compostos Orgânicos/química , Energia Solar , Algoritmos , Elétrons , Estrutura Molecular , Análise Espectral
17.
Ground Water ; 56(6): 959-968, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29417577

RESUMO

Transient confined-unconfined flow conversion caused by pumping in a confined aquifer (i.e., piezometric head drops below the top confined layer) is complicated, partly due to different hydraulic properties between confined and unconfined regions. For understanding mechanism of the transient confined-unconfined conversion, this paper develops a new analytical solution for the transient confined-unconfined flow toward a fully penetrating well in a confined aquifer. The analytical solution is used to investigate the impacts on drawdown simulation by differences of hydraulic properties, including transmissivity, storativity, and diffusivity defined as a ratio of transmissivity and storativity, between the confined and unconfined regions. It is found that neglecting the transmissivity difference may give an overestimation of drawdown. Instead, neglecting the diffusivity difference may lead to an underestimation of drawdown. The shape of drawdown-time curve is sensitive to the change of storativity ratio, S/Sy , between the confined and unconfined regions. With a series of drawdown data from pumping tests, the analytical solution can also be used to inversely estimate following parameters related to the transient confined-unconfined conversion: radial distance of conversion interface, diffusivity, and specific yield of the unconfined region. It is concluded that using constant transmissivity and diffusivity in theory can result in biased estimates of radial distance of the conversion interface and specific yield of the unconfined region in practice. The analytical solution is useful to gain insight about various factors related to the transient confined-unconfined conversion and can be used for the design of mine drainage and groundwater management in the mining area.


Assuntos
Água Subterrânea , Modelos Teóricos , Movimentos da Água
18.
Cell Calcium ; 67: 11-20, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29029785

RESUMO

The brainstem locus coeruleus (LC), the primary norepinephrinergic (NE) nucleus in the brain, has been implicated in the abuse of drugs such as opioids. However, whether and how the LC-NE system is involved in cocaine addiction remains elusive. Here, we demonstrated cocaine-evoked synaptic plasticity of glutamatergic transmission onto LC neurons as one of the earliest traces occurring after a single injection of cocaine. Twenty-four hours after mice were injected intraperitoneally with cocaine, the evoked α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) mediated synaptic transmission onto LC neurons were strongly potentiated without major effect on N-methyl-d-aspartate receptor (NMDAR) mediated synaptic transmission. Compared with saline-pretreated mice, AMPAR-mediated excitatory postsynaptic currents (EPSCs) of cocaine-pretreated mice showed a marked inward rectification, demonstrating the insertion of GluR2-lacking AMPARs to plasma membrane. In addition, the single injection of cocaine did not affect presynaptic glutamate release probability measured by paired pulse ratio. Furthermore, we found that the cocaine-induced potentiation of AMPAR EPSCs could be blocked by prazosin, an inhibitor of α1-adrenoreceptor (AR), indicating that cocaine increases AMPAR transmission via α1-ARs. These results reveal that LC-NE serves as an initial target of drug intake.


Assuntos
Cocaína/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Ácido Glutâmico/metabolismo , Locus Cerúleo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Injeções Intraperitoneais , Locus Cerúleo/citologia , Locus Cerúleo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Microtomia , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/citologia , Neurônios/metabolismo , Técnicas de Patch-Clamp , Prazosina/farmacologia , Receptores de AMPA/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Técnicas de Cultura de Tecidos
19.
Environ Monit Assess ; 187(11): 671, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26439124

RESUMO

The Sakumo wetland is an internationally recognized Ramsar site located in a largely urban area and provides essential ecological and social services to wetland community dwellers. Despite its importance, the wetland has over the years been subjected to human interference resulting in considerable risks of deteriorating water quality, biodiversity loss, and drying up of most parts of the wetland. The conversion of land for residential and agricultural uses has significantly altered the hydrological characteristics of the land surface and modified pathways and flow of water into the wetland. Other drivers identified included drainage (mainly as runoff from agricultural farms), anthropogenic pressure (waste discharge) due to infrastructure development associated with urbanization, chemical contamination as a result of industrial and household pollution, and unsustainable fishing practices (overfishing). The purpose of the study was to review some of the physical and chemical properties of the Sakumo wetland on the changing wetland resources with emphasis on water quality. Rapid urbanization, industrialization, and overexploitation of wetland resources were identified as key causative factors affecting the wetland functions. Their effects on the wetland among others include increased nutrient and toxic chemical load which has resulted in reduced wetland surface water quality and decrease in species diversity. pH of the wetland waters was generally alkaline which is characteristic of water bodies influenced by seawater under oxygenated conditions. The increasing trends of electrical conductivity, phosphates, ammonia, nitrate, and nitrite, though small, point to deteriorating water quality in the wetland. The lagoon water was observed to be heavily polluted with nutrients particularly phosphate. The sequence of nutrient in the wetland was found to be in the order of PO4-P>NH3-N>NO3-N>NO2-N. These, if not checked, will result in further deterioration of the wetland function. In order to protect the wetland structure and function, it is recommended that a determination for both surface water and groundwater (quality and quantity) components of the ecological reserve (aquatic ecosystem) as well as the basic human need should be undertaken. In addition, a complete hydrological study of the wetland must be done. This will enable a well-balanced water allocation scheme to all users while still ensuring long-term survival and sustainability of the wetland.


Assuntos
Monitoramento Ambiental , Ciclo Hidrológico , Áreas Alagadas , Agricultura , Biodiversidade , Ecossistema , Gana , Água Subterrânea , Humanos , Nitratos
20.
Ground Water ; 52 Suppl 1: 208-17, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24597544

RESUMO

Diagnostic derivative interpretation of drawdown data from pumping tests is discussed in this paper. An emphasis is placed on the conceptualization of derivative term of dlgs/dlgt. Use of a combined plot of dlgs/dlgt and ds/dlgt is made to identify various flow patterns from variable discharge tests with infinite conditions, constant rate tests in bounded aquifers, and tests involving double porosity, which can be used to further characterize the aquifer. Compared with the standard derivative method (ds/dlgt), the combined derivative analysis of dlgs/dlgt and ds/dlgt of drawdown behaviours possesses certain advantages identified as follows: (1) the plot of dlgs/dlgt is strikingly sensitive for use in unveiling differences between pumping and recovery periods in a variable discharge test; (2) storativity (S) of pumped aquifers can be accurately evaluated by the combined plot; and (3) a quantitative assessment of double porosity behaviour can also be achieved. Based on applied case studies, Lagrange Interpolation Regression (LIR) is recommended for numerical derivative calculation. Advantages and disadvantages of LIR and traditional methods are demonstrated via a selected case study. The result of the case study confirms that LIR is a preferred method for numerical derivative calculation as it can be used to effectively minimise noisy effect during derivative processes. The proposed derivative approach provides the hydrologists with an additional tool for characterizing pumped aquifers.


Assuntos
Monitoramento Ambiental/métodos , Movimentos da Água , Abastecimento de Água/análise , Poços de Água/análise , Hidrologia , Modelos Teóricos , Porosidade
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