1,942 research outputs found
BIOMECHANICAL ANALYSIS OF TRUNK & LOWER EXTREMITY IN TENNIS SERVE
The purpose of this study was to explore the two different serving pattems---flat serve and spin serve, using a motion analysis system to discover the 3-D kinematic changes of the ankle, knee, hip, pelvis and trunk in the overall serving motion, in conjunction with force plates that helped to measure the ground reaction force (GRF) and worked out the center of pressure (COP). The moment formed by COP with the whole body center of mass would then be analyzed to explore the kinematic characteristics of the body. A further understanding of the role of joints in the lower extremity during a serve will provide a reference to motions and techniques on training and teaching, with a view to improve serving efficiency and avoid sports injury
Molecular characterization of the PhoPQ-PmrD-PmrAB mediated pathway regulating polymyxin B resistance in Klebsiella pneumoniae CG43
<p>Abstract</p> <p>Background</p> <p>The cationic peptide antibiotic polymyxin has recently been reevaluated in the treatment of severe infections caused by gram negative bacteria.</p> <p>Methods</p> <p>In this study, the genetic determinants for capsular polysaccharide level and lipopolysaccharide modification involved in polymyxin B resistance of the opportunistic pathogen <it>Klebsiella pneumoniae </it>were characterized. The expressional control of the genes responsible for the resistance was assessed by a LacZ reporter system. The PmrD connector-mediated regulation for the expression of <it>pmr </it>genes involved in polymyxin B resistance was also demonstrated by DNA EMSA, two-hybrid analysis and <it>in vitro </it>phosphor-transfer assay.</p> <p>Results</p> <p>Deletion of the <it>rcsB</it>, which encoded an activator for the production of capsular polysaccharide, had a minor effect on <it>K. pneumoniae </it>resistance to polymyxin B. On the other hand, deletion of <it>ugd </it>or <it>pmrF </it>gene resulted in a drastic reduction of the resistance. The polymyxin B resistance was shown to be regulated by the two-component response regulators PhoP and PmrA at low magnesium and high iron, respectively. Similar to the control identified in <it>Salmonella</it>, expression of <it>pmrD </it>in <it>K. pneumoniae </it>was dependent on PhoP, the activated PmrD would then bind to PmrA to prolong the phosphorylation state of the PmrA, and eventually turn on the expression of <it>pmr </it>for the resistance to polymyxin B.</p> <p>Conclusions</p> <p>The study reports a role of the capsular polysaccharide level and the <it>pmr </it>genes for <it>K. pneumoniae </it>resistance to polymyxin B. The PmrD connector-mediated pathway in governing the regulation of <it>pmr </it>expression was demonstrated. In comparison to the <it>pmr </it>regulation in <it>Salmonella</it>, PhoP in <it>K. pneumoniae </it>plays a major regulatory role in polymyxin B resistance.</p
Minimally invasive strategy for gynecologic cancer with solitary periacetabular metastasis
SummaryTumor with bone metastases to the periacetabulum is rare, and its surgical management is challenging. Instead of wide excision with reconstruction of the hip joint, we used a relatively noninvasive method to manage periacetabular metastasis. Such a procedure for this condition has the benefits of short surgical time, less bleeding, and fewer complications during surgery. Our surgical management of the case reported here included curettage, phenol cauterization and filling of cisplatin-loaded cement in order to reduce local recurrence. After following-up for 2 years, there was no local recurrence and disease progression
THE RELATIONSHIP BETWEEN SHOULDER PAIN AND SCAPULAR MOBILITY IN TEENAGE BASEBALL PLAYERS
The purpose of this study was to identify the relationship between shoulder pain and scapular mobility for teenage baseball players. Thirty-five teenage baseball players (shoulder pain, n=11; healthy, n=24) were recruited in this study. The lateral scapula slide test (LSST), which represented as scapular mobility, was used to measure the scapular position and symmetry under varying loads. The result of this study showed that there was a difference in distance from the superior angle of the scapula to the spinous process of T2 between the two groups at shoulder 90?abduction
Fuzzy Risk-Based Life Cycle Assessment for Estimating Environmental Aspects in EMS
Environmental aspects plays a central role in environmental management system (EMS) because it is the basis for the identification of an organization-s environmental targets. The
existing methods for the assessment of environmental aspects are grouped into three categories: risk assessment-based (RA-based),
LCA-based and criterion-based methods. To combine the benefits of
these three categories of research, this study proposes an integrated framework, combining RA-, LCA- and criterion-based methods. The
integrated framework incorporates LCA techniques for the identification of the causal linkage for aspect, pathway, receptor and
impact, uses fuzzy logic to assess aspects, considers fuzzy conditions,
in likelihood assessment, and employs a new multi-criteria decision analysis method - multi-criteria and multi-connection comprehensive
assessment (MMCA) - to estimate significant aspects in EMS. The proposed model is verified, using a real case study and the results show
that this method successfully prioritizes the environmental aspects
Atrial fibrillation and electrophysiology in transgenic mice with cardiac-restricted overexpression of FKBP12
Cardiomyocyte-restricted overexpression of FK506-binding protein 12 transgenic (Ī±MyHC-FKBP12) mice develop spontaneous atrial fibrillation (AF). The aim of the present study is to explore the mechanisms underlying the occurrence of AF in Ī±MyHC-FKBP12 mice. Spontaneous AF was documented by telemetry in vivo and Langendorff-perfused hearts of Ī±MyHC-FKBP12 and littermate control mice in vitro. Atrial conduction velocity was evaluated by optical mapping. The patch-clamp technique was applied to determine the potentially altered electrophysiology in atrial myocytes. Channel protein expression levels were evaluated by Western blot analyses. Spontaneous AF was recorded in four of seven Ī±MyHC-FKBP12 mice but in none of eight nontransgenic (NTG) controls. Atrial conduction velocity was significantly reduced in Ī±MyHC-FKBP12 hearts compared with NTG hearts. Interestingly, the mean action potential duration at 50% but not 90% was significantly prolonged in Ī±MyHC-FKBP12 atrial myocytes compared with their NTG counterparts. Consistent with decreased conduction velocity, average peak Na+ current ( INa) density was dramatically reduced and the INa inactivation curve was shifted by approximately +7 mV in Ī±MyHC-FKBP12 atrial myocytes, whereas the activation and recovery curves were unaltered. The Nav1.5 expression level was significantly reduced in Ī±MyHC-FKBP12 atria. Furthermore, we found increases in atrial Cav1.2 protein levels and peak L-type Ca2+ current density and increased levels of fibrosis in Ī±MyHC-FKBP12 atria. In summary, cardiomyocyte-restricted overexpression of FKBP12 reduces the atrial Nav1.5 expression level and mean peak INa, which is associated with increased peak L-type Ca2+ current and interstitial fibrosis in atria. The combined electrophysiological and structural changes facilitated the development of local conduction block and altered action potential duration and spontaneous AF. NEW & NOTEWORTHY This study addresses a long-standing riddle regarding the role of FK506-binding protein 12 in cardiac physiology. The work provides further evidence that FK506-binding protein 12 is a critical component for regulating voltage-gated sodium current and in so doing has an important role in arrhythmogenic physiology, such as atrial fibrillation
A Novel RFID Authentication Protocol based on Elliptic Curve Cryptosystem
Recently, many researchers have proposed RFID authentication protocols. These protocols are mainly consists of two types: symmetric key based and asymmetric key based. The symmetric key based systems usually have some weaknesses such as suffering brute force, de-synchronization, impersonation, and tracing attacks. In addition, the asymmetric key based systems usually suffer from impersonation, man-in-the-middle, physical, and tracing attacks. To get rid of those weaknesses and reduce the system workload, we adopt elliptic curve cryptosystem (ECC) to construct an asymmetric key based RFID authentication system. Our scheme needs only two passes and can resist various kinds of attacks. It not only outperforms the other RFID schemes having the same security level but also is the most efficient
An efficient RFID mutual authentication scheme based on ECC
Recently, Radio Frequency Identification (RFID) technique has been widely deployed in many applications, such as medical drugs management in hospitals and missing children searching in amusement parks. The applications basically can be classified into two types: non-public key cryptosystem (PKC)-based and PKC-based. However, many of them have been found to be flawed in the aspect of privacy problem. Therefore, many researchers tried to resolve this problem. They mainly investigated on how low-cost RFID tags can be used in large-scale systems. However, after analyses, we found those studies have some problems, such as suffering physical attack or de-synch attack. Hence, in this paper, we try to design an efficient RFID scheme based on Elliptic Curve Cryptography (ECC) to avoid these problems. After analyses, we conclude that our scheme not only can resist various kinds of attacks but also outperforms the other ECC based RFID schemes in security requirements, with needing only little extra elliptic curve point multiplications
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