27 research outputs found
A review of medicinal herbs in the management of male infertility
Male infertility can be caused by a variety of factors, including neurohormonal imbalances, reproductive tissue disturbances, and qualitative and quantitative degradation of semen. There is a global decline in male reproductive health, and modern therapeutic options to tackle male infertility are expensive, less accessible and have extended treatment durations and adverse effects. When it comes to male reproductive health, herbal therapies are in a much better position to provide more holistic approaches. As aphrodisiacs, a unique class of herbs defined in herbal pharmacology, nourish and stimulate the body's sexual tissues. A careful evaluation of the current information on drugs and their probable functions in treating male infertility is the purpose of this paper
Cross-attention-based saliency inference for predicting cancer metastasis on whole slide images
Although multiple instance learning (MIL) methods are widely used for
automatic tumor detection on whole slide images (WSI), they suffer from the
extreme class imbalance within the small tumor WSIs. This occurs when the tumor
comprises only a few isolated cells. For early detection, it is of utmost
importance that MIL algorithms can identify small tumors, even when they are
less than 1% of the size of the WSI. Existing studies have attempted to address
this issue using attention-based architectures and instance selection-based
methodologies, but have not yielded significant improvements. This paper
proposes cross-attention-based salient instance inference MIL (CASiiMIL), which
involves a novel saliency-informed attention mechanism, to identify breast
cancer lymph node micro-metastasis on WSIs without the need for any
annotations. Apart from this new attention mechanism, we introduce a negative
representation learning algorithm to facilitate the learning of
saliency-informed attention weights for improved sensitivity on tumor WSIs. The
proposed model outperforms the state-of-the-art MIL methods on two popular
tumor metastasis detection datasets, and demonstrates great cross-center
generalizability. In addition, it exhibits excellent accuracy in classifying
WSIs with small tumor lesions. Moreover, we show that the proposed model has
excellent interpretability attributed to the saliency-informed attention
weights. We strongly believe that the proposed method will pave the way for
training algorithms for early tumor detection on large datasets where acquiring
fine-grained annotations is practically impossible
Performance prediction of erosive wear of steel for two-phase flow in an inverse U-bend
Erosion of the elbow due to non-Newtonian viscous slurry flows is often observed in hydrocarbon transportation pipelines. This paper intends to study the erosion behavior of double offset U-bends and 180 degrees U-bends for two-phase (liquid-sand) flow. A numerical simulation was conducted using the Discrete Phase Model (DPM) on carbon steel pipe bends with a 40 mm diameter and an R/D ratio of 1.5. The validity of the erosion model has been established by comparing it with the results quantified in the literature by experiment. While the maximum erosive wear rates of all evaluated cases were found to be quite different, the maximum erosion locations have been identified between 150 degrees and 180 degrees downstream at the outer curvature. It was seen that with the increase in disperse phase diameter, the erosive wear rate and impact area increased. Moreover, with the change of configuration from a 180 degrees U-bend to a double offset U-bend, the influence of turbulence on the transit of the disperse phase decreases as the flow approaches downstream and results in less erosive wear in a double offset U-bend. Furthermore, the simulation results manifest that the erosive wear increases with an increase in flow velocity, and the erosion rate of the double offset U-bend was nearly 8.58 times less than the 180 degrees U-bend for a carrier fluid velocity of 2 m/s and 1.82 times less for 4 m/s carrier fluid velocity. The erosion rate of the double offset U-bend was reduced by 120% compared to the 180 degrees U-bend for 6 m/s in liquid-solid flow.Web of Science1516art. no. 555
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
Integrated Consequence Modelling for Fire Radiation and Combustion Product Toxicity in offshore Petroleum Platform using Risk Based Approach
The processing area of offshore platform has high probability of leakage of hydrocarbons. Liquefied Natural Gas (LNG) is one of the most common hydrocarbon produced in offshore platforms. Leakage of LNG can cause pool fire, jet fire, flash fire or fire ball. Thermal radiations due to fire is the major source of damage to workers on board. But due to fire, various combustion product toxic gases are also produced that have both acute and chronic health effects. These toxic gases can cause incapacitation, increased heart rate, vomiting and even death. Predicting the human injury due to thermal radiations and concentration of toxic gases are the key issues. A risk based approach takes in to consideration the duration a worker spent on different location of offshore platform and also it has the additive ability to evaluate overall risk due to fire radiation and toxic gases. Grid based approach helps in better visualization of risk posed by fire radiation and combustion product toxic gases at different locations of platform. The current study proposed an integrated consequence modelling approach for fire and combustion product toxic gases using risk based and grid based approaches. The integrated accident is modelled using Computational Fluid Dynamics (CFD) code Fire Dynamics Simulator (FDS). The results showed that risk posed by thermal radiation is confined on sub cellar deck (lower deck) but estimated risk due to combustion product gas (carbon monoxide) on cellar deck (upper deck) has significant value that needs to be considered. The current approach would be useful for emergency preparedness plans and safety measures designs for offshore platforms
A Parametric Study to Investigate Human Injury and Fatality due to Vapor Cloud Explosion
The processing area of an offshore platform consists of various equipment for handling, separation and transferring of crude oil and natural gas. Consequently, the chances of an accidental release are quite high as compared to other areas. Among the major hazard posed on an offshore platform, Vapor Cloud Explosion (VCE) is the fatal one. Among the various factors that impact the resulting overpressure developed due to VCE: leak rates, wind speeds, and wind directions are the important ones. The current paper investigates the effect of these factors (leak rates, wind speeds and wind directions) on explosion strength on an offshore platform. The release, dispersion and resulting VCE are modelled by utilizing Computational Fluid Dynamics (CFD) software Flame Acceleration Simulator (FLACS). Furthermore, risk estimation for human injury/fatality (risk of eardrum rupture, head impact, and whole-body displacement) has been done considering these factors using probit models. The results showed that these factors (leak rates, wind speeds, and wind directions) have a major impact on resulting explosion strength and consequently, on the risk of human injury/fatality. Risk of head impact is quite high while risk of eardrum rupture and whole-body displacement is low. The current study can be useful in designing effective safety measures to reduce the impact of such accidents
Predicting the Structural Reliability of LNG Processing Plate-Fin Heat Exchanger for Energy Conservation
Liquefied natural gas (LNG) is one of the hydrocarbon fuels with the least carbon footprint having a rapidly rising global share in the prime energy market. LNG processing for transportation at longer distances works under cryogenic conditions, especially when used for liquefaction and gasification applications. The supply chain of the eco-environmental friendly hydrocarbon is heavily dependent on the processing plant used for liquefaction and subsequent re-gasification of the natural gas. Plate-fin heat exchangers are extensively used in the LNG industry for both re-gasification as well as liquefaction processes. The exchange of heat during the process of natural gas phase change involves plate-fin heat exchangers working under cryogenic low-temperature conditions. The heat exchangers are designed to have brazed joints that are most vulnerable to failure under these temperature conditions. One failure of such a joint can not only hinder the supply chain but also may result in fire and life hazards. In almost all earlier studies, analytical and numerical methods were used to analyze these braze joints using finite element method methods and examining the stresses while keeping them at or near to ambient conditions. In this research, the plate-fin heat exchanger is investigated for its structural stability of brazed fins for three different fin configurations: plain, wavy and compound having different joint geometries. In addition, the analyses are carried out using experimentally measured brazed joint strength which is measured to be on average 22% lower than the base material strength owing to brazing process and resultant heat-affected zone (HAZ). Therefore, the reliability is assessed for these joints in terms of factor of safety (FOS) while keeping in view the actual yield criteria. It was found that the structural stability of compound fins configuration is weakest amongst all considered fin configurations. The failure of the compound fin brazed joint is expected to be along the horizontal path of the joint due to yielding. The study also predicts the life of the fin brazed joints in different joining directions with different topologies of fins commonly recommended in the literature. It is observed that the commonly recommended safe fin geometries are predicted to be susceptible to failure if a reduction in the brazed joint is considered. The analysis and recommendation in this paper shall provide a reliable and safe design approach for plate-fin exchangers for different operating conditions especially in low to cryogenic temperature applications
Finite element analysis of silver nanorods, spheres, ellipsoids and core-shell structures for hyperthermia treatment of cancer
The finite element analysis technique was used to investigate the suitability of silver nanorods, spheres, ellipsoids and core-shell structures for the hyperthermia treatment of cancer. The temperature of the silver nanostructures was raised from 42 to 46 & DEG;C, in order to kill the cancerous cells. The time taken by the nanostructures to attain this temperature, with external source heating, was also estimated. The heat transfer module in COMSOL Multiphysics was used for the finite element analysis of hyperthermia, based on silver nanostructures. The thermal response of different shapes of silver nanostructures was evaluated by placing them inside the spherical domain of the tumor tissue. The proposed geometries were heated at different time intervals. Optimization of the geometries was performed to achieve the best treatment temperature. It was observed that silver nanorods quickly attain the desired temperature, as compared to other shapes. The silver nanorods achieved the highest temperature of 44.3 & DEG;C among all the analyzed geometries. Moreover, the central volume, used to identify the thermal response, was the maximum for the silver nano-ellipsoids. Thermal equilibrium in the treatment region was attained after 0.5 mu s of heating, which made these structures suitable for hyperthermia treatment.Web of Science155art. no. 178