Plasmonic nanostructures have been recently investigated as a possible way to improve absorption of light in solar cells. The strong interaction of small metal nanostructures with light allows ...control over the propagation of light at the nanoscale and thus the design of ultrathin solar cells in which light is trapped in the active layer and efficiently absorbed. In this paper we review some of our recent work in the field of plasmonics for improved solar cells. We have investigated two possible ways of integrating metal nanoparticles in a solar cell. First, a layer of Ag nanoparticles that improves the standard antireflection coating used for crystalline and amorphous silicon solar cells has been designed and fabricated. Second, regular and random arrays of metal nanostructures have been designed to couple light in waveguide modes of thin semiconductor layers. Using a large-scale, relative inexpensive nano-imprint technique, we have designed a back-contact light trapping surface for a-Si:H solar cells which show enhanced efficiency over standard randomly textured cells.
Involuntary movements, or dyskinesia, represent a debilitating complication of levodopa therapy for Parkinson's disease. Taking advantage of a monkey brain bank constituted to study the ...pathophysiology of levodopa-induced dyskinesia, we here report the changes affecting D1, D2 and D3 dopamine receptors within the striatum of four experimental groups of non-human primates: normal, parkinsonian, parkinsonian treated with levodopa without or with dyskinesia. We also report the possible role of arrestin and G protein-coupled receptor kinases.
We report the discovery, cloning, and characterization of a novel human matrix metalloproteinase 26 (MMP-26) (matrixin) gene, endometase, an endometrial tumor-derivedmetalloproteinase. Among more ...than three million expressed sequence tags sequenced, the endometase gene was only obtained from human endometrial tumor cDNA library. Endometase mRNA was expressed specifically in human uterus, not in other tissues/cells tested, e.g. testis, heart, brain, lungs, liver, thymus, and melanoma G361. Endometase protein has a signal peptide, a propeptide domain, and a catalytic domain with a unique “cysteine switch” propeptide sequence, PHCGVPDGSD, and a zinc-binding motif, VATHEIGHSLGLQH. Endometase is 43, 41, 41, and 39% identical to human metalloelastase, stromelysin, collagenase-3, and matrilysin, respectively. The zymogen was expressed and isolated from Escherichia coli as inclusion bodies with a molecular mass of 28 kDa. The identity and homogeneity of the recombinant protein was confirmed by protein N-terminal sequencing, silver stain, and immunoblot analyses. The pro-enzyme was partially activated during the folding process. Endometase selectively cleaved type I gelatin and α1-proteinase inhibitor; however, it did not digest collagens, laminin, elastin, β-casein, plasminogen, soybean trypsin inhibitor, or Bowman-Birk inhibitor. It hydrolyzed peptide substrates of matrixins and tumor necrosis factor-α converting enzyme. Endometase may selectively cleave extracellular matrix proteins, inactivate serpins, and process cytokines.
Controlled nanostructuring of thin-film solar cells offers a promising route toward increased efficiency through improved light trapping. Many such light trapping designs involve structuring of the ...active region itself. Optimization of these designs is aided by the use of computer simulations that account for both the optics and electronics of the device. We describe such a simulation-based approach that accounts for experimental tradeoffs between high-aspect ratio structuring and electronic material quality. Our model explicitly accounts for localized regions of degraded material quality that is induced by light trapping structures in n-i-p a-Si:H solar cells. We find that the geometry of the defects couples to the geometry of light absorption profiles in the active region and that this coupling impacts the spectral response of the device. Our approach yields insights into the nanoscale device physics that is associated with localized geometry-induced defects and provides a framework for full optoelectronic optimization.
The history of minimum temperatures at 50 and 70 mb is examined from NMC, UK Met O and ECMWF analyses. MSU channel 24 data are similarly inspected. South Pole sonde data are used to calculate ...saturation humidity mixing ratio as a function of altitude and time throughout 1987. Saturation with respect to ice could be maintained for water mixing ratios of 3.5 ppmv for a period of about 80 days from mid-June to mid-September. Dehydration to mixing ratios of 1 ppmv or less was possible sporadically. Data from the ER-2 flights between 53 S and 72 S are used in conjunction with particle size measurements and air parcel trajectories to demonstrate the dehydration occurring over Antarctica. Water mixing ratios at the latitude of Punta Arens (53 S), in conjunction with tracer measurements and trajectory analysis, show that at potential temperatures from about 325 to 400 K, the dryness (less than 3 ppmv) had its origin over Antarctica rather than in the tropics. Water mixing ratios within the Antarctic vortex varied from 1.5 to 3.8 ppmv, with a strong isentropic gradient being evident in the region of high potential vorticity gradients.
The COVID-19 pandemic is putting health professionals under increasing pressure. This population is already acknowledged to be at risk of burnout.
We aim to provide a 'snapshot' of the levels of ...burnout, anxiety, depression and distress among healthcare workers during the COVID-19 pandemic.
We distributed an online survey via social media in June 2020 open to any UK healthcare worker. The primary outcome measure was symptoms of burnout measured using the Copenhagen Burnout Inventory. Secondary outcomes of depression, anxiety, distress and subjective measures of stress were also recorded. Multivariate logistic regression analysis was performed to identify factors associated with burnout, depression, anxiety and distress.
A total of 539 persons responded to the survey; 90% female and 53% nurses. Participants with moderate-to-severe burnout were younger (49% vs. 33% under 40 years, P = 0.004), more likely to have pre-existing comorbidities (21% vs. 12%, P = 0.031), twice as likely to have been redeployed from their usual role (22% vs. 11%; P = 0.042), or to work in an area dedicated to COVID-19 patients (50% vs. 32%, P < 0.001) and were almost 4 times more likely to have previous depression (24% vs. 7%; P = 0.012).
Independent predictors of burnout were being younger, redeployment, exposure to patients with COVID-19, being female and a history of depression. Evaluation of existing psychological support interventions is required with targeted approaches to ensure support is available to those most at risk.
High-sensitivity cardiac troponin assays enable myocardial infarction to be ruled out earlier, but the optimal approach is uncertain. We compared the European Society of Cardiology rule-out pathway ...with a pathway that incorporates lower cardiac troponin concentrations to risk stratify patients.
Patients with suspected acute coronary syndrome (n=1218) underwent high-sensitivity cardiac troponin I measurement at presentation and 3 and 6 or 12 hours. We compared the European Society of Cardiology pathway (<99th centile at presentation or at 3 hours if symptoms <6 hours) with a pathway developed in the High-STEACS study (High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary
yndrome) population (<5 ng/L at presentation or change <3 ng/L and <99th centile at 3 hours). The primary outcome was a comparison of the negative predictive value of both pathways for index type 1 myocardial infarction or type 1 myocardial infarction or cardiac death at 30 days. We evaluated the primary outcome in prespecified subgroups stratified by age, sex, time of symptom onset, and known ischemic heart disease.
The primary outcome occurred in 15.7% (191 of 1218) patients. In those less than the 99th centile at presentation, the European Society of Cardiology pathway ruled out myocardial infarction in 28.1% (342 of 1218) and 78.9% (961 of 1218) at presentation and 3 hours, respectively, missing 18 index and two 30-day events (negative predictive value, 97.9%; 95% confidence interval, 96.9-98.7). The High-STEACS pathway ruled out 40.7% (496 of 1218) and 74.2% (904 of 1218) at presentation and 3 hours, missing 2 index and two 30-day events (negative predictive value, 99.5%; 95% confidence interval, 99.0-99.9;
<0.001 for comparison). The negative predictive value of the High-STEACS pathway was greater than the European Society of Cardiology pathway overall (
<0.001) and in all subgroups, including those presenting early or known to have ischemic heart disease.
Use of the High-STEACS pathway incorporating low high-sensitivity cardiac troponin concentrations rules out myocardial infarction in more patients at presentation and misses 5-fold fewer index myocardial infarctions than guideline-approved pathways based exclusively on the 99th centile.
URL: http://clinicaltrials.gov. Unique identifier: NCT01852123.
Objective To evaluate the diagnosis of myocardial infarction using a high sensitivity troponin I assay and sex specific diagnostic thresholds in men and women with suspected acute coronary ...syndrome.Design Prospective cohort study.Setting Regional cardiac centre, United Kingdom.Participants Consecutive patients with suspected acute coronary syndrome (n=1126, 46% women). Two cardiologists independently adjudicated the diagnosis of myocardial infarction by using a high sensitivity troponin I assay with sex specific diagnostic thresholds (men 34 ng/L, women 16 ng/L) and compared with current practice where a contemporary assay (50 ng/L, single threshold) was used to guide care.Main outcome measure Diagnosis of myocardial infarction.Results The high sensitivity troponin I assay noticeably increased the diagnosis of myocardial infarction in women (from 11% to 22%; P<0.001) but had a minimal effect in men (from 19% to 21%, P=0.002). Women were less likely than men to be referred to a cardiologist or undergo coronary revascularisation (P<0.05 for both). At 12 months, women with undisclosed increases in troponin concentration (17-49 ng/L) and those with myocardial infarction (≥50 ng/L) had the highest rate of death or reinfarction compared with women without (≤16 ng/L) myocardial infarction (25%, 24%, and 4%, respectively; P<0.001).Conclusions Although having little effect in men, a high sensitivity troponin assay with sex specific diagnostic thresholds may double the diagnosis of myocardial infarction in women and identify those at high risk of reinfarction and death. Whether use of sex specific diagnostic thresholds will improve outcomes and tackle inequalities in the treatment of women with suspected acute coronary syndrome requires urgent attention.
Background Sex-specific criteria are recommended for the diagnosis of myocardial infarction, but the impact of these on presenting characteristics is unknown. Methods and Results We evaluated ...patient-reported symptoms in 1941 patients (39% women) with suspected acute coronary syndrome attending the emergency department in a substudy of a prospective trial. Standardized criteria defined typical and atypical presentations based on pain nature, location, radiation, and additional symptoms. Diagnosis of myocardial infarction was adjudicated using a high-sensitivity cardiac troponin I assay with sex-specific thresholds (>16 ng/L women, >34 ng/L men). Patients identified who were missed by the contemporary assay with a uniform threshold (≥50 ng/L) were reclassified by this approach. Type 1 myocardial infarction was diagnosed in 16% (184/1185) of men and 12% (90/756) of women, with 9 (5%) men and 27 (30%) women reclassified using high-sensitivity cardiac troponin I and sex-specific thresholds. Chest pain was the presenting symptom in 91% (1081/1185) of men and 92% (698/756) of women. Typical symptoms were more common in women than in men with myocardial infarction (77% 69/90 versus 59% 109/184; P=0.007), and differences were similar in those reclassified (74% 20/27 versus 44% 4/9; P=0.22). The presence of ≥3 typical features was associated with a positive likelihood ratio for the diagnosis of myocardial infarction in women (positive likelihood ratio, 1.18; 95% CI, 1.03-1.31) but not in men (positive likelihood ratio 1.09; 95% CI, 0.96-1.24). Conclusions Typical symptoms are more common and have greater predictive value in women than in men with myocardial infarction whether or not they are diagnosed using sex-specific criteria. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier NCT01852123.
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