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Since the raise of 2D materials, significant research has been dedicated to their strain-dependent electronic and mechanical properties. In this work, we studied exciton energies and low-frequency phonon modes in CVD-grown mono- and few-layer WS2 transferred on PDMS micropillars. The modification of the band structure under strain was investigated by photoluminescence (PL) spectroscopy at room temperature. Machine learning (ML) methods were used to analyze the PL spatial maps and facilitate the spectral deconvolution. For monolayer (1L) WS2, red shift in the exciton energy was detected as a function of the position, which was ascribed to the presence of residual strain. For three-layer (3L) strained WS2, a significant increase in the PL intensity corresponding to direct (K–K) band transition together with a change of exciton energy was observed. From the PL spectra, strain distribution maps were extracted for both studied samples, which strongly resembled the ML clustering results. Finally, the low-frequency Raman modes of WS2 were studied on both Si/SiO2 and PDMS substrates and no significant change of their frequency was observed for the 3L-WS2. [ABSTRACT FROM AUTHOR]

Background:  Thoracoscopic repair of esophageal atresia (EA) with tracheoesophageal fistula (TEF) is becoming an increasingly widespread technique; there is still controversy about its indication in certain patients. Our objective is to analyze if potential risk factors such as major congenital heart disease (CHD) or low birth weight (LBW) are a limitation to this approach., Methods:  Retrospective study (2017-2021) of patients with EA and distal TEF who underwent thoracoscopic repair were included. Patients with LBW less than 2,000 g or major CHD were compared with the rest., Results:  Twenty-five patients underwent thoracoscopic surgery. Nine patients (36%) had major CHD. Five of them (20%) were LBW less than 2,000 g, and only 8% (2/25) presented both risk factors. There were no differences in terms of operative time, conversion rate, tolerance evaluated with gasometric parameters (pO 2 , pCO 2 , pH) or complications (anastomotic leak and stricture, both early or during follow-up) in patients with major CHD and LBW (1,473 ± 319 vs. 2,664 ± 402 g). One conversion to thoracotomy was performed in a neonate weighing 1,050 g due to anesthetic intolerance. There was no recurrence of TEF. One patient died at the age of 9 months, due to major uncorrectable heart disease., Conclusion:  Thoracoscopic repair of EA/TEF is feasible technique in patients with CHD or LBW, with similar results to other patients. The complexity of this technique warrants individualizing the indication in each case., Level of Evidence:  IV., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: To investigate the GH response to glucagon in adult patients with GH deficiency and in controls compared with the GH response to the insulin tolerance test (ITT) in patients with GH deficiency and to determine whether the use of glucagon results in a diagnostic utility test., Patients and Design: Seventy-three patients with adult GH deficiency and organic hypothalamic-pituitary disease were recruited, along with 46 controls. The patients were divided into five groups according to the number of associated hormone deficiencies present., Measurements: Hypopituitary subjects underwent assessment of GH secretory status by the ITT, the glucagon test and measurement of serum IGF-I concentration. Controls underwent the glucagon test. After the ITT, glucose and GH levels were measured at baseline, 30, 60 and 90 minutes, and after glucagon at baseline, 90, 120, 150, 180, 210 and 240 minutes., Results: The highest GH value after the ITT in the patient group was 3 microg/l (0.76 +/- 0.82 microg/l), and after the glucagon test the highest GH peak value was 2.9 microg/l (0.64 +/- 0.79 microg/l). A correlation was found between the GH peak and the progressive number of hormone deficiencies. After the glucagon test, the GH peak obtained in the controls at 180 minutes was 9.8 +/- 4.6 microg/l and, on an individual basis, none of the 46 controls failed to achieve peak GH levels higher than 3 microg/l. In the controls, a negative correlation was observed between the GH response to glucagon and age (r = -0.389, P = 0.0075) and body mass index (r = -0.329, P = 0.0254). The accuracy of the glucagon test for differentiating patients from controls, estimated by receiver operating characteristics (ROC) curve methodology, showed that the cut-off of 3 microg/l for the GH peak provides 100% sensitivity and 100% specificity and is a reliable decision threshold., Conclusions: The glucagon GH test is reliable and provides a clear separation between GH-deficient and normal adults. A single glucagon test with a cut-off of 3 microg/l for the GH peak is diagnostic of GH deficiency in adults and could be considered and studied as an alternative to the ITT.

Cryopreservation is an effective method of islet storage and may facilitate clinical trials of islet transplantation. It was the aim of the present study to evaluate the in vitro viability of cryopreserved rat islets, including the response to nonglucose secretagogues and glucose oxidation. After pancreatic digestion via intraductal injection of collagenase, 75- to 200-micron Wistar rat islets were handpicked and cultured in RPMI 1640 (glucose 11.1 mmol/L) and randomized into two groups: control (cultured 20 to 24 hours at 37 degrees C) and cryopreserved (after 20 to 24 hours of culture at 37 degrees C, islets were cryopreserved according to Rajotte's protocol: freezing velocity, -0.25 degree C/min; thawing velocity, 200 degrees C/min). In the two groups, we evaluated recovery, insulin content per islet, staining viability (ethidium bromide/orange acridine; semiquantitative scoring, measuring the viable area of the islet from 0 = less viable to 3 = more viable), insulin secretion after glucose and nonglucose secretagogues, and oxidation of D-[U-14C]glucose. The results for the control group were always higher for the following: recovery (95.4% +/- 1.2% v 83.0% +/- 2.1%, P = .00), insulin content (2,203.9 +/- 335.2 v 1,443.3 +/- 171.8 microU/islet, P = .03), insulin secretion after 5.5 mmol/L glucose (61.3 +/- 8.0 v 28.3 +/- 3.4 microU/islet/90 min, p = .00), 16.7 mmol/L glucose (151.4 +/- 16.1 v 98.7 +/- 14.1 microU/islet/90 min, p = .03), 10 mmol/L L-leucine +10 mmol/L L-glutamine (125.6 +/- 27.9 v 56.8 +/- 6.4 microU/islet/90 min, P = .05), and 10 mmol/L L-arginine (202.5 +/- 27.5 v 128.8 +/- 14.2 microU/islet/90 min, P = .01), and glucose oxidation at 5.5 mmol/L (12.5 +/- 1.1 v 7.9 +/- 0.6 pmol/islet/120 min, P = .00) and at 16.7 mmol/L (26.1 +/- 2.6 v 14.3 +/- 1.6 pmol/islet/120 min, P = .00). No significant differences in staining viability were found between groups (2.35 and 2.48, respectively, P = .55). However, cryopreserved and control islets showed a significant increase in insulin secretion and glucose oxidation after increasing the glucose concentration from 5.5 to 16.7 mmol/L. We conclude that when glucose is increased, cryopreserved islets keep the capacity to increase insulin secretion, but cryopreservation produces a significant decrease in several islet viability characteristics. This decrease may be due to a decline of beta-cell number per islet and/or a decrease in the content of insulin per beta cell.

To evaluate the role of metabolic control at the beginning of insulin-dependent diabetes mellitus (IDDM) in the development of diabetic retinopathy (DR) a cross-sectional study was performed with a retrospective analysis of 24 patients followed for at least seven years. The following parameters were investigated: 1) At IDDM diagnosis, age, sex, metabolic control (basal serum glucose, HbA1, cholesterol, triglycerides) and endogen insulin secretion (EIS). 2) At one year in the follow-up: EIS. 3) Since IDDM diagnosis and every 3-4 months: body mass index, dose and pattern of insulin administration and metabolic control. 4) At seven years in the follow-up: direct ophthalmoscopy, fluorescein angiography, microalbuminuria and blood pressure. In the seventh year of follow-up five patients (23.8%; 95% CI: 8.2%-47.2%) developed changes in fluorescein angiography secondary to IDDM. Compared with patients with normal fluorescein angiography their metabolic control was poorer (mean HbA1--seven years--: 11.7 +/- 0.5 versus 9.8 +/- 0.3%; p = 0.01); mean basal glycemia--seven years--: 214 +/- 13.3 versus 174 +/- 7.7 mg/dl; p = 0.03) and their systolic blood pressure (SBP) higher (124 +/- 5.5 versus 111 +/- 2.8 mmHg; p = 0.04). Logistic regression revealed that mean HbA1 values for seven years was the only independent risk factor significantly associated with the development of DR (p = 0.04). The conclusion is that in patients with IDDM of short duration, the development of DR is associated with a deficient glucose control and a higher SBP.

Objective: Genetic analysis is now essential for the accurate screening of families with multiple endocrine neoplasia type 2 (MEN2). We present the genetic analyses by both haplotype and direct RET proto-oncogene mutation analysis in seven Mediterranean MEN 2A families and have compared these results with biochemical screening tests and pathological examinations., Design: Total DNA was extracted from leucocytes. Linkage analysis was performed using five RFLP systems from three loci that flank the MEN2A locus (FNRB, RBP3, D10S15). RET proto-oncogene analysis was carried out by automatic DNA sequencing and adequate digestion of PCR amplified products for exons 10 and 11. Screening for medullary thyroid carcinoma or C-cell hyperplasia was performed by the pentagastrin provocation test. Adrenal medullary function was assessed by measurements of 24-hour urinary excretion of catecholamines and their metabolites. Serum calcium and phosphate measurements were the initial screen for hyperparathyroidism. Serum PTH was determined only if hyperparathyroidism was suggested by the former determinations., Patient: Genetic study was performed in 59 individuals (39 at risk) from seven kindreds of Mediterranean origin with MEN 2A., Results: Diagnosis by linkage analysis was not possible in 30% of individuals at risk, but RET proto-oncogene analysis identified all these individuals. Mutations of the RET proto-oncogene were detected in exon 10 (codon 618) in one MEN 2A kindred and in exon 11 (codon 634) in the others. The results of direct analysis were concordant with linkage studies in each case. Three individuals from different MEN 2A kindreds, who were subsequently shown not to be gene carriers, had false positive pentagastrin stimulation tests., Conclusion: Biochemical tests can be replaced by direct DNA mutation analysis as the first line screening test in order to identify gene carriers of MEN 2A.

The Cushing syndrome during pregnancy is very infrequent, being even more so that of hypophysary etiology despite corticotropic adenomas being more prevalent in fertile-aged women. Its diagnosis is difficult since it may be confused with the physiologic alterations of the cortisol and the ACTH which occur during pregnancy. The treatment is controversial. In the cases reported to date, pregnancy represented a worsening of the picture. The case of a patient diagnosed with Cushing disease during the first trimester of pregnancy is presented. The hypercorticism improved clinically and biochemically during the pregnancy with no maternofetal complications observed. The disease activity continued following delivery.

Unlabelled: To assess risk factors associated with microalbuminuria development in short-term evolution insulin-dependent diabetes mellitus (IDDM) we undertake a cross-sectional study with retrospective examination of the 34 patients diagnosed with IDDM between 1982 and 1983 and followed up for at least 7 years in an outpatient endocrinology clinic., Main Measures: (1) At IDDM diagnosis: age, sex, parameters of metabolic control (fasting glycemia, HbA1), islet-cell antibodies, insulin autoantibodies, endogenous insulin secretion (EIS) and HLA type. (2) At 1 year evolution: EIS re-evaluation. (3) From IDDM diagnosis (every 3-4 month): body mass index, insulin schedule and dose, and parameters of metabolic control. (4) At 7-year evolution: 24-h urinary albumin excretion (UAE) and arterial blood pressure measurements on two consecutive outpatient controls. Microalbuminuria was defined as UAE above 30 micrograms/min on the two consecutive measurements. After 7-year follow-up, 8 (23.5%; 95% Cl: 9.3 to 37.7%) patients developed microalbuminuria. Their metabolic control was worse (7 years mean HbA1: 10.7 vs. 9.7%; P = 0.04) and 1 year EIS lower (1.9 vs. 7.6 ng/ml.10 min; P = 0.03) than in normoalbuminuric patients. They also had higher prevalence of 'high-normal' arterial blood pressure (P = 0.03) and diabetic retinopathy (P = 0.01) than normoalbuminuric patients did. Stepwise logistic regression analysis showed that diabetic retinopathy was the only independent and significant risk factor related to microalbuminuria development (P = 0.01). We conclude that in subjects with short-term evolution IDDM, microalbuminuria development was associated with glycemic control, EIS and arterial blood pressure levels, however the strongest association was found with diabetic retinopathy occurrence.