1,728 research outputs found
Deficiency of Mkrn2 causes abnormal spermiogenesis and spermiation, and impairs male fertility.
Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation
Research on Static Tension Ratio Characteristic of Double-Vessel Friction Hoist System Components
Double-vessel multi-rope friction hoist system, of which the lifting, starting, running, and braking must meet the safety conditions in operation. Non-skid safety boundary conditions were originally determined by Euler’s formula. In order to avoid the complex task of check and check-again calculation in the friction hoist system design. In this research, static tension ratio c, which was closely bonded with anti-skid design was directly brought into the analysis and research on the system. As a result, characteristic of static tension ratio c of component quality of friction hoist system was found, which offers a simple, sound and reliable theoretical foundation for the anti-skid and optimization of system configuration
Prevalence of hyperuricemia and its related risk factors in healthy adults from Northern and Northeastern Chinese provinces
BACKGROUND: Hyperuricemia (HUA) is a potential risk factor for developing insulin resistance, hypertension, dyslipidemia and cardiovascular disease. Therefore, we studied the prevalence of HUA and associated risk factors in the population of two provinces in northern China. METHODS: Based on the research of Chinese Physiological Constant and Health Conditions conducted in 2008–2010, we enrolled 29,639 subjects in a randomized, stratified study in four sampling areas in Heilongjiang Province and the Inner Mongolia Autonomous Region. We collected 13,140 serum samples to determine biochemical indicators including uric acid(UA), glucose, blood lipids, liver function, and renal function, and finally a representative sample of 8439 aged 18 years and older was determined. We also defined and stratified HUA, hypertension, diabetes, obesity and lipid abnormalities according to international guidelines. RESULTS: There were significant differences in the UA levels between different genders and regions. The total prevalence of HUA is 13.7%. Men had a higher prevalence of HUA than women (21% vs. 7.9%; P < 0.0001). As age increased, HUA prevalence decreased in men but rose in women. The suburbs of big cities had the highest HUA prevalence (18.7%), and in high-prevalence areas the proportion of women with HUA also increased. A stepwise logistic regression model was used to filter out twelve HUA risk factors, including age, gender, residence, hypercholesterolemia, hypertriglyceridemia, impaired fasting glucose, hypertension, obesity, abdominal obesity, CKD, drinking and sleeping. After adjusting for these factors, the odds ratio of HUA was 1.92 times higher in men than in women. Compared with agricultural and pastoral areas, the odds ratio of having HUA was 2.14 for participants in the suburbs of big cities and 1.57 in the center of big cities. CONCLUSIONS: The prevalence of HUA is high in northern China. The differences in HUA prevalence by geographic region suggested that unbalanced economic development and health education, therefore HUA prevention measures should be strengthened to improve quality of life and reduce health care costs
Toward physical realizations of thermodynamic resource theories
Conventional statistical mechanics describes large systems and averages over
many particles or over many trials. But work, heat, and entropy impact the
small scales that experimentalists can increasingly control, e.g., in
single-molecule experiments. The statistical mechanics of small scales has been
quantified with two toolkits developed in quantum information theory: resource
theories and one-shot information theory. The field has boomed recently, but
the theorems amassed have hardly impacted experiments. Can thermodynamic
resource theories be realized experimentally? Via what steps can we shift the
theory toward physical realizations? Should we care? I present eleven
opportunities in physically realizing thermodynamic resource theories.Comment: Publication information added. Cosmetic change
Page Curve and Phase Transition in deformed Jackiw-Teitelboim Gravity
We consider the entanglement island in a deformed Jackiw-Teitelboim black
hole in the presence of the phase transition. This black hole has the van der
Waals-Maxwell-like phase structure as it is coupled with a Maxwell field. We
study the behavior of the Page curve of this black hole by using the island
paradigm. In the fixed charge ensemble, we discuss different situations with
different charges that influence the system's phase structure. There is only a
Hawking-Page phase transition in the absence of charges, which leads to an
unstable small black hole. Hence, the related Page curve does not exist.
However, a van der Waals-Maxwell-like phase transition occurs in the presence
of charges. This yields three black hole solutions. The Page curve of the
middle size black hole does not exist. For the extremal black hole, the Page
time approaches zero in the phase transition situation but becomes divergent
without the phase transition. In a word, we study the Page curve and the island
paradigm for different black hole phases and in different phase transition
situations.Comment: 28 pages, 13 figures, references added, published versio
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
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