202 research outputs found
On the Development and Application of FOG
Gyroscope is a type of angular velocity measuring device, which can precisely determine the orientation of moving objects. It was first employed in navigation and later became an inertial navigation instrument widely used in modern aviation, aerospace, and national defense industries. As a vital representative of gyroscope, the fiber-optic gyroscope (FOG) has advantages in terms of compact structure, high precision, high sensitivity, and high environmental adaptability. FOG has been broadly utilized in many fields, and is also a key component of modern navigation instruments. In this paper, the history, classification, performance indicators, and application requirements of gyroscope are briefly summarized. The development history of FOG based on Sagnac effect is described in detail. The three generations of FOG are interferometric FOG, resonant FOG, and stimulated Brillouin scattering FOG. At the same time, this chapter summarizes the development and research situation of FOG in the United States, Japan, France, and other major developing countries, and compares the application of FOG in various international companies
The mutual interactions among Helicobacter pylori, chronic gastritis, and the gut microbiota: a population-based study in Jinjiang, Fujian
ObjectivesHelicobacter pylori (H. pylori) is a type of bacteria that infects the stomach lining, and it is a major cause of chronic gastritis (CG). H. pylori infection can influence the composition of the gastric microbiota. Additionally, alterations in the gut microbiome have been associated with various health conditions, including gastrointestinal disorders. The dysbiosis in gut microbiota of human is associated with the decreased secretion of gastric acid. Chronic atrophic gastritis (CAG) and H. pylori infection are also causes of reduced gastric acid secretion. However, the specific details of how H. pylori infection and CG, especially for CAG, influence the gut microbiome can vary and are still an area of ongoing investigation. The incidence of CAG and infection rate of H. pylori has obvious regional characteristics, and Fujian Province in China is a high incidence area of CAG as well as H. pylori infection. We aimed to characterize the microbial changes and find potential diagnostic markers associated with infection of H. pylori as well as CG of subjects in Jinjiang City, Fujian Province, China.ParticipantsEnrollment involved sequencing the 16S rRNA gene in fecal samples from 176 cases, adhering to stringent inclusion and exclusion criteria. For our study, we included healthy volunteers (Normal), individuals with chronic non-atrophic gastritis (CNAG), and those with CAG from Fujian, China. The aim was to assess gut microbiome dysbiosis based on various histopathological features. QIIME and LEfSe analyses were performed. There were 176 cases, comprising 126 individuals who tested negative for H. pylori and 50 who tested positive defined by C14 urea breath tests and histopathological findings in biopsies obtained through endoscopy. CAG was also staged by applying OLGIM system.ResultsWhen merging the outcomes from 16S rRNA gene sequencing results, there were no notable variations in alpha diversity among the following groups: Normal, CNAG, and CAG; OLGIM I and OLGIM II; and H. pylori positive [Hp (+)] and H. pylori negative [Hp (–)] groups. Beta diversity among different groups show significant separation through the NMDS diagrams. LEfSe analyses confirmed 2, 3, and 6 bacterial species were in abundance in the Normal, CNAG, and CAG groups; 26 and 2 species in the OLGIM I and OLGIM II group; 22 significant phylotypes were identified in Hp (+) and Hp (–) group, 21 and 1, respectively; 9 bacterial species exhibited significant differences between individuals with CG who were Hp (+) and those who were Hp (–).ConclusionThe study uncovered notable distinctions in the characteristics of gut microbiota among the following groups: Normal, CNAG, and CAG; OLGIM I and OLGIM II; and Hp (+) and Hp (–) groups. Through the analysis of H. pylori infection in CNAG and CAG groups, we found the gut microbiota characteristics of different group show significant difference because of H. pylori infection. Several bacterial genera could potentially serve as diagnostic markers for H. pylori infection and the progression of CG
SEA-LEVEL CHANGES RECORDED BY CERIUM ANOMALIES IN THE LATE JURASSIC (TITHONIAN) BLACK ROCK SERIES OF QIANGTANG BASIN, NORTH-CENTRAL TIBET; pp. 18–35
The Upper Jurassic black rock series of the Amdo area of north-central Tibet have attracted attention because of its organic-rich matter and oil seepage in the rock series. Abundant ammonites of Aulacosphinctes and Virgatosphinctes as well as bivalves including Buchia and Chlamys, are well preserved in the Qiangmuleiqu Formation of the Middle to Late Tithonian (Late Jurassic). The total rare earth elements (âREE) abundance of the formation varies from 18.814 to 46.818Â ppm and is lower than that of an average in marine shales. Inter-element correlations suggest that the shale-normalized REE patterns provide the information about the origin of sedimentary rocks (i.e., not affected by diagenesis), and can be used as a potential indicator for eustatic sea-level changes. The Ceanom values gradually increased from â0.015 to â0.238 from the lower to middle part of the series, indicating a rise in sea level. The Ceanom then dropped to â0.081, suggesting a lowering of sea level. From the middle to upper part of the section, there are two more sea-level fluctuations indicated by variations of cerium anomaly values. Thus, sea-level fluctuations occurred three times in this Late Jurassic section, with major episodes of eustatic rise took place in the lower-middle part of this section. These episodic cycles show that the sediments in the Amdo area of north-central Qiangtang basin were deposited in continental shelf or deep-water continental slope environments, which is not in agreement with the previous views that there are no deep-water sediments in Qiangtang basin. Our results call for further studies to be underÂtaken on Jurassic stratigraphic framework and tectono-sedimentary evoluÂtion in Qiangtang basin, northern Tibet
Abnormal Resting-State Functional Connectivity in the Whole Brain in Lifelong Premature Ejaculation Patients Based on Machine Learning Approach
Recent neuroimaging studies have indicated that abnormalities in brain structure and function may play an important role in the etiology of lifelong premature ejaculation (LPE). LPE patients have exhibited aberrant cortical structure, altered brain network function and abnormal brain activation in response to erotic pictures. However, it remains unclear whether resting-state whole brain functional connectivity (FC) is altered in LPE patients. Machine learning analysis has the advantage of screening the best classification features from high-throughput data (such as FC), which has the potential to identify the pathophysiological targets of disease by establishing classification indicators for patients and healthy controls (HCs). Therefore, the supported vector machine based classification model using FC as features was used in the present study to confirm the most specific FCs that distinguish LPE patients from healthy controls. After feature selection, the remained features were used to build the classification model, with an accuracy 0.85 ± 0.14, sensitivity of 0.92 ± 0.18, specificity of 0.72 ± 0.30, and recall index of 0.85 ± 0.17 across 1000 testing groups (100 times 10-folds cross validation). After that, two-sample t-tests with family-wise error correction were used to compare these features that occur more than 500 times during training steps between LPE patients and HCs. Four FCs, (1) between left medial part of orbital frontal cortex (mOFC) and right mOFC, (2) between the left rectus and right postcentral gyrus, (3) between the right insula and left pallidum, and (4) between the right middle part of temporal pole and right inferior part of temporal gyrus showed significant group difference. These results demonstrate that resting-state brain FC might be a discriminating feature to distinguish LPE patients from HCs. These classification features, especially the FC between bilateral mOFC, provide underlying abnormal central functional targets in LPE etiology, which offers a novel alternative target for future intervention in LPE treatment
A flexible Cu-based catalyst system for the transformation of fructose to furanyl ethers as potential bio-fuels
Abstract(#br)Biomass-derived furanyl ethers, such as 5-alkoxymethylfurfurals (AMFs) and 2,5-bis(alkoxymethyl)furans (BAMFs), can be employed as promising biofuels or additives. The development of multifunctional catalysts for the efficient production of furanyl ethers from sugars through 5-hydroxymethylfurfural (HMF) as an intermediate is highly desirable but challenging, because multiple reactions including dehydration, etherification and hydrogenation get involved and the side reaction of sugars and HMF to form humins is inevitable. In this contribution, we found that the introduction of CuO resulted in the generation of Lewis acid sites at the cost of Bronsted acid sites over CuO-USY catalysts through the formation of Al-O-Cu(II) species. The dispersity of CuO particles and the amount of Lewis acid sites could be manipulated by adjusting the loading of CuO. If 5 wt% CuO was supported on USY zeolite to give a CuO(5)-USY catalyst, CuO particles with a high dispersity (36.4%) afforded abundant Lewis acid sites (457.1 μ mol/g). Lewis acid over CuO(5)-USY greatly promoted the acid-catalyzed dehydration of fructose to HMF and HMF etherification to AMFs, resulting in a HMF yield up to 86.2% from fructose and AMFs yields greater than 90% from HMF. Interestingly, a combination of CuO(5)-USY and a small amount of metallic Cu powder was able to offer desirable BAMFs yields by the reductive etherification of HMF under hydrogen atmosphere. As a result, 5-methoxymethylfurfural (MMF) of 79.6% and 2,5-bis(methoxymethyl)furan (BMMF) yield of 74.5% were achieved from fructose through HMF as an intermediate in the presence of CuO(5)-USY alone or with metallic Cu as a co-catalyst. Therefore, the above Cu-based catalyst system holds the promise to flexibly produce a family of AMFs or BAMFs from fructose via a facile two-step approach
miR-499-5p Attenuates Mitochondrial Fission and Cell Apoptosis via p21 in Doxorubicin Cardiotoxicity
Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its cardiotoxicity limits its clinical application. A better understanding of the molecular mechanisms underlying DOX cardiotoxicity will benefit clinical practice and remedy heart failure. Our present study observed that DOX caused cardiomyocyte (H9c2) apoptosis via the induction of abnormal mitochondrial fission. Notably, the expression levels of p21 increased in DOX-treated cardiomyocytes, and the silencing of p21 using siRNA greatly attenuated mitochondrial fission and apoptosis in cardiomyocytes. We also found that miR-499-5p could directly target p21 and attenuated DOX-induced mitochondrial fission and apoptosis. The role of the miR-499-5p-p21 axis in the prevention of DOX cardiotoxicity was also validated in the mice model. DOX treatment induced an upregulation of p21, which induced subsequent abnormal mitochondrial fission and myocardial apoptosis in mouse heart. Adenovirus-harboring miR-499-5p-overexpressing mice exhibited significantly reduced p21 expression, mitochondrial fission and myocardial apoptosis in hearts following DOX administration. The miR-499-5p-overexpressing mice also exhibited improved cardiomyocyte hypertrophy and cardiac function after DOX treatment. However, miR-499-5p was not involved in the DOX-induced apoptosis of cancer cells. Taken together, these findings reveal an emerging role of p21 in the regulation of mitochondrial fission program. miR-499-5p attenuated mitochondrial fission and DOX cardiotoxicity via the targeting of p21. These results provide new evidence for the miR-499-5p-p21 axis in the attenuation of DOX cardiotoxicity. The development of new therapeutic strategies based on the miR-499-5p-p21 axis is a promising path to overcome DOX cardiotoxicity as a chemotherapy for cancer treatment
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Properties of Generalized Offset Curves and Surfaces
This paper proposes a definition of generalized offsets for curves and surfaces, which have the variable offset distance and direction, by using
the local coordinate system. Based on this definition, some analytic properties and theorems of generalized offsets are put forward. The regularity and the topological property of generalized offsets are simply given by representing the generalized offset as the standard offset. Some examples are provided as well to show the applications of generalized offsets. The conclusions in this paper can be taken as the foundation for further study on extending the standard offset
Properties of Generalized Offset Curves and Surfaces
Fujian Provincial Natural Science Foundation of China [2012J01013]; Panjinlong Discipline Construction Foundation of Jimei University, China [ZC2012022]This paper proposes a definition of generalized offsets for curves and surfaces, which have the variable offset distance and direction, by using the local coordinate system. Based on this definition, some analytic properties and theorems of generalized offsets are put forward. The regularity and the topological property of generalized offsets are simply given by representing the generalized offset as the standard offset. Some examples are provided as well to show the applications of generalized offsets. The conclusions in this paper can be taken as the foundation for further study on extending the standard offset
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