STUDY OF THROWING WEIGHT AND THROWING POWER FOR MALE DISCUS THROWERS

INTRODUCTION: Throwing power means the rate at which muscles work when throwers are doing throwing movements. It depends on the strength and speed of the thrower. The purpose of this paper is to research the relation between throwing weight and throwing power, to advance the best exercise weight in special strength training for male discus throwers, and to proved scientific basis for effective speed strength training

THE EFFECTS OF SHOT WEIGHT ON THROWING POWER OUTPUT IN ELITE FEMALE SHOT PUTTTERS

INTRODUCTION: Sport specific strength development is one of the key factors of the efficient training for throwing athletes (Liu, 1996). Little research has been conducted to examine the appropriate weight of shot that could develop specific strength and promote maximum power output in shot put. The purpose of this study was to compare the power and strength output induced by different weight selected for shot-put exercise in elite female shot putters

In vitro isolation of class-specific oligonucleotide-based small-molecule receptors

Class-specific bioreceptors are highly desirable for recognizing structurally similar small molecules, but the generation of such affinity elements has proven challenging. We here develop a novel ‘parallel-and-serial’ selection strategy for isolating class-specific oligonucleotide-based receptors (aptamers) in vitro. This strategy first entails parallel selection to selectively enrich cross-reactive binding sequences, followed by serial selection that enriches aptamers binding to a designated target family. As a demonstration, we isolate a class-specific DNA aptamer against a family of designer drugs known as synthetic cathinones. The aptamer binds to 12 diverse synthetic cathinones with nanomolar affinity and does not respond to 11 structurally similar non-target compounds, some of which differ from the cathinone targets by a single atom. This is the first account of an aptamer exhibiting a combination of broad target cross-reactivity, high affinity and remarkable specificity. Leveraging the qualities of this aptamer, instantaneous colorimetric detection of synthetic cathinones at nanomolar concentrations in biological samples is achieved. Our findings significantly expand the binding capabilities of aptamers as class-specific bioreceptors and further demonstrate the power of rationally designed selection strategies for isolating customized aptamers with desired binding profiles. We believe that our aptamer isolation approach can be broadly applied to isolate class-specific aptamers for various small molecule families

Inhibition of Connexin 43 Hemichannels Alleviates Cerebral Ischemia/Reperfusion Injury via the TLR4 Signaling Pathway

Connexin 43 (Cx43) widely exists in all components of the neurovascular unit (NVU) and is a constituent of gap junctions and hemichannels. In physiological states, gap junctions are open for regular intercellular communication, and the hemichannels present low open probability in astrocytes. After cerebral ischemia, a large number of hemichannels are unusually opened, leading to cell swelling and even death. Most known hemichannel blockers also inhibit gap junctions and sequentially obstruct normal electrical cell-cell communication. In this study, we tested the hypothesis that Gap19, a selective Cx43-hemichannel inhibitor, exhibited neuroprotective effects on cerebral ischemia/reperfusion (I/R). An obvious improvement in neurological scores and infarct volume reduction were observed in Gap19-treated mice after brain ischemia induced by middle cerebral artery occlusion (MCAO). Gap19 treatment attenuated white matter damage. Moreover, Gap19 treatment suppressed the expression of Cx43 and Toll-like receptor 4 (TLR4) pathway-relevant proteins and prevented the overexpression of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). To further explore downstream signaling, we established an in vitro model–oxygen glucose deprivation (OGD) to simulate ischemic conditions. Immunofluorescence staining showed that Cx43 co-existed with TLR4 in astrocytes. The hemichannel activity was increased after OGD and Gap19 could inhibit this effect on astrocytes. Gap19 substantially improved relative cell vitality and decreased the expression of Cx43, TLR4 and inflammatory cytokines in vitro. In addition, in the lipopolysaccharide (LPS) stimulation OGD model, Gap19 also exhibited a protective effect via inhibiting TLR4 pathway activation. In summary, our results showed that Gap19 exerted a neuroprotective effect after stroke via inhibition of the TLR4-mediated signaling pathway

Photocatalytic abstraction of hydrogen atoms from water using hydroxylated graphitic carbon nitride for hydrogenative coupling reactions

Employing pure water, the ultimate green source of hydrogen donor to initiate chemical reactions that involve a hydrogen atom transfer (HAT) step is fascinating but challenging due to its large H−O bond dissociation energy (BDEH-O=5.1 eV). Many approaches have been explored to stimulate water for hydrogenative reactions, but the efficiency and productivity still require significant enhancement. Here, we show that the surface hydroxylated graphitic carbon nitride (gCN−OH) only requires 2.25 eV to activate H−O bonds in water, enabling abstraction of hydrogen atoms via dehydrogenation of pure water into hydrogen peroxide under visible light irradiation. The gCN−OH presents a stable catalytic performance for hydrogenative N−N coupling, pinacol-type coupling and dehalogenative C−C coupling, all with high yield and efficiency, even under solar radiation, featuring extensive impacts in using renewable energy for a cleaner process in dye, electronic, and pharmaceutical industries

Face Aging Using Deep Convolutional Generative Adversarial Network with Condition

We explore multiple ideas on face aging, and we finally settle down on constructing a Face Reconstruction Convolutional Neural Network and a Feature Vector Encoder. Together with a discriminator on age and a discriminator on the distribution of the feature vectors, we are able to generate the face aging transition both forward and backward for a given face, with a known age and a known gender. We make comment on the effectiveness of the discriminators mentioned above, which are included in the model in order to enhance the performance. Our results have shown that the inclusion of both discriminators are effective in different ways

Development of Electrochemical Aptamer-based Sensors for Sensitive and Specific Detection of Small-molecule Targets

Electrochemical aptamer-based (E-AB) sensors have been applied for diverse applications such as forensic science, pharmaceutical diagnostics, food safety, environmental monitoring, and personal medical care due to their rapid, accurate, and specific detection of analytes in complex samples. However, limited sensitivity and a lack of portable devices for point-of-care applications have greatly hindered the maturation of E-AB sensors from proof-of-concept designs to commercial systems. This dissertation describes several novel strategies to improve the sensitivities of E-AB sensors and fabricate portable paper-based devices to remedy these problems. We first detail the development of a novel approach to utilize a defined mixture of two bioreceptors that exhibit different binding profiles to tune the sensitivity and extend the dynamic range of E-AB sensors for the detection and analysis of drug families. We successfully measure 12 synthetic cathinones, a family of dangerous illicit designer drugs, with high cross-reactivity while minimizing the influence of 17 interferents. We then further enhance the sensitivity of E-AB sensors from the microscale level by developing a generalizable target-assisted immobilization strategy to control the spatial morphology of aptamers modified onto the electrode surface and thereby achieve maximum signal output. We immobilize the aptamers in a bound and folded state to ensure that the modified aptamers have sufficient space for efficient target-induced folding and signal transduction. This approach greatly improves E-AB sensor sensitivity and signal-to-noise ratio (SNR) compared to sensors fabricated by conventional methods. Finally, building on the optimal E-AB sensor design developed in my first two projects, we focus on developing portable paper-based electrochemical devices to convert these E-AB sensors from benchtop-based platforms to on-site applications. Specifically, we utilize filter paper to fabricate multiplexed aptamer-modified paper electrochemical devices (mPEDs) via ambient vacuum filtration. The fabrication process is simple, low-cost, and environmentally friendly. Moreover, the resulting postage stamp-sized paper-based devices are portable, enabling accurate and specific multianalyte detection in a microliter of a single biological sample within seconds. We believe our paper-based devices have the potential to enable sensitive and precise on-site detection for multiple analytes