1,585 research outputs found
Experimental Evidence for Partially Dehydrogenated epsilon-FeOOH
Hydrogen in hydrous minerals becomes highly mobile as it approaches the geotherm of the lower mantle. Its diffusion and transportation behaviors under high pressure are important in order to understand the crystallographic properties of hydrous minerals. However, they are difficult to characterize due to the limit of weak X-ray signals from hydrogen. In this study, we measured the volume changes of hydrous Δ-FeOOH under quasi-hydrostatic and non-hydrostatic conditions. Its equation of states was set as the cap line to compare with Δ-FeOOH reheated and decompression from the higher pressure pyrite-FeO2Hx phase with 0 < x < 1. We found the volumes of those re-crystallized Δ-FeOOH were generally 2.2% to 2.7% lower than fully hydrogenated Δ-FeOOH. Our observations indicated that Δ-FeOOH transformed from pyrite-FeO2Hx may inherit the hydrogen loss that occurred at the pyrite-phase. Hydrous minerals with partial dehydrogenation like Δ-FeOOHx may bring it to a shallower depth (e.g., < 1700 km) of the lower mantle
Mapping Irrigated and Rainfed Wheat Areas Using Multi-Temporal Satellite Data
Irrigation is crucial to agriculture in arid and semi-arid areas and significantly contributes to crop development, food diversity and the sustainability of agro-ecosystems. For a specific crop, the separation of its irrigated and rainfed areas is difficult, because their phenology is similar and therefore less distinguishable, especially when there are phenology shifts due to various factors, such as elevation and latitude. In this study, we present a simple, but robust method to map irrigated and rainfed wheat areas in a semi-arid region of China. We used the Normalized Difference Vegetation Index (NDVI) at a 30 Ă 30 m spatial resolution derived from the Chinese HJ-1A/B (HuanJing(HJ) means environment in Chinese) satellite to create a time series spanning the whole growth period of wheat from September 2010 to July 2011. The maximum NDVI and time-integrated NDVI (TIN) that usually exhibit significant differences between irrigated and rainfed wheat were selected to establish a classification model using a support vector machine (SVM) algorithm. The overall accuracy of the Google-Earth testing samples was 96.0%, indicating that the classification results are accurate. The estimated irrigated-to-rainfed ratio was 4.4:5.6, close to the estimates provided by the agricultural sector in Shanxi Province. Our results illustrate that the SVM classification model can effectively avoid empirical thresholds in supervised classification and realistically capture the magnitude and spatial patterns of rainfed and irrigated wheat areas. The approach in this study can be applied to map irrigated/rainfed areas in other regions when field observational data are available
Increased levels of soluble CD226 in sera accompanied by decreased membrane CD226 expression on peripheral blood mononuclear cells from cancer patients
<p>Abstract</p> <p>Background</p> <p>As a cellular membrane triggering receptor, CD226 is involved in the NK cell- or CTL-mediated lysis of tumor cells of different origin, including freshly isolated tumor cells and tumor cell lines. Here, we evaluated soluble CD226 (sCD226) levels in sera, and membrane CD226 (mCD226) expression on peripheral blood mononuclear cells (PBMC) from cancer patients as well as normal subjects, and demonstrated the possible function and origin of the altered sCD226, which may provide useful information for understanding the mechanisms of tumor escape and for immunodiagnosis and immunotherapy.</p> <p>Results</p> <p>Soluble CD226 levels in serum samples from cancer patients were significantly higher than those in healthy individuals (<it>P </it>< 0.001), while cancer patients exhibited lower PBMC mCD226 expression than healthy individuals (<it>P </it>< 0.001). CD226-Fc fusion protein could significantly inhibit the cytotoxicity of NK cells against K562 cells in a dose-dependent manner. Furthermore, three kinds of protease inhibitors could notably increase mCD226 expression on PMA-stimulated PBMCs and Jurkat cells with a decrease in the sCD226 level in the cell culture supernatant.</p> <p>Conclusion</p> <p>These findings suggest that sCD226 might be shed from cell membranes by certain proteases, and, further, sCD226 may be used as a predictor for monitoring cancer, and more important, a possible immunotherapy target, which may be useful in clinical application.</p
Harder Tasks Need More Experts: Dynamic Routing in MoE Models
In this paper, we introduce a novel dynamic expert selection framework for
Mixture of Experts (MoE) models, aiming to enhance computational efficiency and
model performance by adjusting the number of activated experts based on input
difficulty. Unlike traditional MoE approaches that rely on fixed Top-K routing,
which activates a predetermined number of experts regardless of the input's
complexity, our method dynamically selects experts based on the confidence
level in expert selection for each input. This allows for a more efficient
utilization of computational resources, activating more experts for complex
tasks requiring advanced reasoning and fewer for simpler tasks. Through
extensive evaluations, our dynamic routing method demonstrates substantial
improvements over conventional Top-2 routing across various benchmarks,
achieving an average improvement of 0.7% with less than 90% activated
parameters. Further analysis shows our model dispatches more experts to tasks
requiring complex reasoning skills, like BBH, confirming its ability to
dynamically allocate computational resources in alignment with the input's
complexity. Our findings also highlight a variation in the number of experts
needed across different layers of the transformer model, offering insights into
the potential for designing heterogeneous MoE frameworks. The code and models
are available at https://github.com/ZhenweiAn/Dynamic_MoE
Microsurgical vasovasostomy for the treatment of intractable chronic scrotal pain after vasectomy
Dear Editor, We present herein two rare cases of intractable chronic scrotal pain after vasectomy. The patients were effectively treated with microsurgical vasovasostomy (MVV). We also discuss the possible aetiologies of the pain and other surgical options. Vasectomy was once the most common method of permanent contraception for men in both China and worldwide. One particularly distressing complication after vasectomy is chronic scrotal pain, which is defined as intermittent or constant, unilateral or bilateral scrotal pain for o3 months. The pain is intense enough to interfere with the patient's daily activities and prompts him to seek medical attention. 1 Although its aetiology remains unclear, epididymal congestion, painful sperm granulomas, vascular stasis and nerve impingement have been postulated as possible aetiologic factors. 2 Non-surgical options have been used successfully to treat chronic scrotal pain after vasectomy, including scrotal support, thermal therapy, limiting activity, non-steroidal anti-inflammatory drugs, narcotic analgesics, antibiotics, neuroleptics, spermatic cord nerve block, biofeedback and psychiatric evaluation. Surgical options include reversal of the vasectomy, microsurgical spermatic cord denervation, granuloma excision, epididymectomy and orchidectomy. The microsurgical techniques used for vasectomy reversal have changed significantly in the past decade, culminating in the standard surgical procedures used today, and its indications include a desire to have more children (remarriage or after the death of a child), treatment of post-vasectomy pain and treatment of obstructive azoospermia due to traumatic or iatrogenic injury of vas deferens. 3 To our knowledge, we report the first cases of the use of MVV for the treatment of intractable chronic scrotal pain after vasectomy in a Chinese hospital. The 72-year-old and 49-year-old men presented with a more than 20-year history of intractable, chronic scrotal pain after vasectomy. They had consulted various urologists and had undergone numerous attempted therapies in other hospitals. They reported a history of vasectomy more than 30 years and 20 years previously, respectively. They did not have any histories of haematuria, haematospermia, lower urinary tract symptoms, epididymitis, prostatitis or testicular trauma. Their physical examination was unremarkable, and both the secondary sexual characteristics and genital examination were normal. The testes were descended bilaterally and normal in size and consistency. The caput epididymides exhibited dilatation and tenderness. The vasa deferentia were palpated for painful lumps at the vasectomy sites. Digital rectal examination was unremarkable for prostatic abnormalities. Each patient underwent Doppler ultrasonography of the testes and urinary tract, urinalysis, urine culture and spermiogram to exclude primary or secondary causes of pain, including intratesticular infection, tumours and ureteral lithiasis. At our initial consultation, the patients were asked to complete a pain and psychological questionnaire, which included pain, depression and anxiety scores. The pain score (Visual Analogue Scale) was in the form of an 11-point numerical rating score with 0 representing 'no pain' and 10 representing the 'worst possible pain'. The patients' preoperative pain scores were 5 and 6 points, respectively. The depression scores (Self-rating Depression Scale) were in the form of an 80-point numerical rating score; a score less than 50 indicated 'normal', and a score greater than 50 indicated 'depression'. The depression scores of the two patients were 35 and 38 points, respectively. The anxiety scores (Self-rating Anxiety Scale) were in the form of an 80-point numerical rating score; scores less than 50 were considered to indicate 'normal', whereas scores greater than 50 indicated 'anxiety'. The anxiety scores of the two patients were 33 and 32 points, respectively. Spermatic cord block was performed once for each patient with 6 ml of 1% lidocaine and 1 ml of methylprednisolone (40 mg). The patients had 3 and 7 days of complete pain relief after the blockade, respectively. The study protocol was approved by the Ethical Committee of the First Affiliated Hospital of Sun Yat-Sen University, and informed consent was signed by the patients. The patients were offered MVV as a more permanent solution in March and July 2012, respectively. Scrotal exploration was performed with the patients under combined spinal-epidural anaesthesia. The left-side incision (3 cm) of the scrotum through the tunica vaginalis was made, and the left vas deferens was delivered through this incision. The painful lumps and nerveimpinging tissue at the vasectomy site were thoroughly resected by electrocautery. Distal patency was confirmed by infusing diluted methylene blue through the abdominal side of the vas deferens, resulting in blue colouring of the urine. A 123 to 153 operating microscope (Leica Microsystems (Schweiz) AG, Heerbrugg, Switzerland) was use
Evaluating the efficiency of a nomogram based on the data of neurosurgical intensive care unit patients to predict pulmonary infection of multidrug-resistant Acinetobacter baumannii
BackgroundPulmonary infection caused by multidrug-resistant Acinetobacter baumannii (MDR-AB) is a common and serious complication after brain injury. There are no definitive methods for its prediction and it is usually accompanied by a poor prognosis. This study aimed to construct and evaluate a nomogram based on patient data from the neurosurgical intensive care unit (NSICU) to predict the probability of MDR-AB pulmonary infection.MethodsIn this study, we retrospectively collected patient clinical profiles, early laboratory test results, and doctorsâ prescriptions (66 variables). Univariate and backward stepwise regression analyses were used to screen the variables to identify predictors, and a nomogram was built in the primary cohort based on the results of a logistic regression model. Discriminatory validity, calibration validity, and clinical utility were evaluated using validation cohort 1 based on receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA). For external validation based on predictors, we prospectively collected information from patients as validation cohort 2.ResultsAmong 2115 patients admitted to the NSICU between December 1, 2019, and December 31, 2021, 217 were eligible for the study, including 102 patients with MDR-AB infections (102 cases) and 115 patients with other bacterial infections (115 cases). We randomly categorized the patients into the primary cohort (70%, N=152) and validation cohort 1 (30%, N=65). Validation cohort 2 consisted of 24 patients admitted to the NSICU between January 1, 2022, and March 31, 2022, whose clinical information was prospectively collected according to predictors. The nomogram, consisting of only six predictors (age, NSICU stay, Glasgow Coma Scale, meropenem, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio), had significantly high sensitivity and specificity (primary cohort AUC=0.913, validation cohort 1 AUC=0.830, validation cohort 2 AUC=0.889) for early identification of infection and had great calibration (validation cohort 1,2 P=0.3801, 0.6274). DCA confirmed that the nomogram is clinically useful.ConclusionOur nomogram could help clinicians make early predictions regarding the onset of pulmonary infection caused by MDR-AB and implement targeted interventions
Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta
Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector,
the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are
measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and
(7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure
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