Time resolved Fabry-Perot measurements of cavity temperature in pulsed QCLs.

Temperature rise during operation is a central concern of semiconductor lasers and especially difficult to measure during a pulsed operation. We present a technique for in situ time-resolved temperature measurement of quantum cascade lasers operating in a pulsed mode at ~9.25 µm emission wavelength. Using a step-scan approach with 5 ns resolution, we measure the temporal evolution of the spectral density, observing longitudinal Fabry-Perot modes that correspond to different transverse modes. Considering the multiple thin layers that make up the active layer and the associated Kapitza resistance, thermal properties of QCLs are significantly different than bulk-like laser diodes where this approach was successfully used. Compounded by the lattice expansion and refractive index changes due to time-dependent temperature rise, Fabry-Perot modes were observed and analyzed from the time-resolved emission spectra of quantum cascade lasers to deduce the cavity temperature. Temperature rise of a QCL in a pulsed mode operation between -160 °C to -80 °C was measured as a function of time. Using the temporal temperature variations, a thermal model was constructed that led to the extraction of cavity thermal conductivity in agreement with previous results. Critical in maximizing pulsed output power, the effect of the duty cycle on the evolution of laser heating was studied in situ, leading to a heat map to guide the operation of pulsed lasers.

Monitoring macroplastics in aquatic and terrestrial ecosystems: Expert survey reveals visual and drone-based census as most effective techniques.

Anthropogenic litter, such as plastic, is investigated by the global scientific community from various fields employing diverse techniques. The goal is to assess and finally mitigate the pollutants' impacts on the natural environment. Plastic litter can accumulate in different matrices of aquatic and terrestrial ecosystems, impacting both biota and ecosystem functioning. Detection and quantification of macroplastics, and other litter, can be realized by jointly using visual census and remote sensing techniques. The primary objective of this research was to identify the most effective approach for monitoring macroplastic litter in riverine and marine environments through a comprehensive survey based on the experiences of the scientific community. Researchers involved in plastic pollution evaluated four litter occurrence and flux investigation methods (visual census, drone-based surveys, satellite imagery, and GPS/GNSS trackers) through a questionnaire. Traditional visual census and drone deployment were deemed as the most popular approaches among the 46 surveyed researchers, while satellite imagery and GPS/GNSS trackers received lower scores due to limited field validation and short performance ranges, respectively. On a scale from 0 to 5, visual census and drone-based surveys obtained 3.5 and 2.0, respectively, whereas satellite imagery and alternative solutions received scores lower than 1.2. Visual and drone censuses were used in high, medium and low-income countries, while satellite census and GPS/GNSS trackers were mostly used in high-income countries. This work provides an overview of the advantages and drawbacks of litter investigation techniques, contributing i) to the global harmonization of macroplastic litter monitoring and ii) providing a starting point for researchers and water managers approaching this topic. This work supports the selection and design of reliable and cost-effective monitoring approaches to mitigate the ambiguity in macroplastic data collection, contributing to the global harmonization of macroplastic litter monitoring protocols.

Laser induced sponge-like Si in Si-rich oxides for photovoltaics.

We show that a sponge-like structure of interconnected Si nanowires embedded in a dielectric matrix can be obtained by laser annealing of silicon rich oxides (SRO). Due to quantum confinement, the large bandgap displayed by these percolated nanostructures can be utilized as a tandem stage in 3rd generation thin-film solar cells. Well passivated by the SiO2 dielectric matrix, they are expected to overcome the difficulty of carrier separation encountered in the case of isolated crystalline quantum dots. In this study PECVD grown SRO were irradiated by a cw Ar⁺ laser. Raman spectroscopy has been used to assess the crystallinity of the Si nanostructures and thus to optimize the annealing conditions as dwell times and power densities. In addition, Si plasmon imaging in the transmission electron microscope was applied to identify the sponge-like structure of phase-separated silicon.

Elephantiasis nostras verrucosa on the abdomen of a Turkish female patient caused by morbid obesity.

Elephantiasis Nostras Verrucosa is a rare disorder of an extremity or a body region, which is associated with chronic lymphedema. There are 7 reported cases of abdominal elephantiasis in the medical literature. Here we report a morbidly obese female patient with elephantiasis nostras verrucosa on the abdominal wall.

Plasma viscosity, an early cardiovascular risk factor in women with subclinical hypothyroidism.

OBJECTIVE: It is controversial, if subclinical hypothyroidism increases cardiovascular risk. Plasma viscosity is a hemorheological parameter, which is accepted as an early cardiovascular risk factor. We investigated the alterations in plasma viscosity in women with subclinical hypothyroidism. DESIGN: 40 female patients with subclinical hypothyroidism and 31 age- and weight-matched healthy women were included. Free thyroxine (FT4), thyroid stimulating hormone (TSH), lipid parameters, fibrinogen, C-reactive protein (CRP) levels, hematocrit and plasma viscosity were measured in all subjects. MAIN OUTCOME: Plasma viscosity, total cholesterol and low density lipoprotein were significantly increased and high density lipoprotein was significantly decreased in patients with subclinical hypothyroidism. No significant correlation was found among the parameters. CONCLUSION: Increased plasma viscosity in patients' group suggests that cardiovascular risk might be increased in patients with subclinical hypothyroidism. As far as we could reach, this is the first study concerning plasma viscosity in subclinical hypothyroidism.

Simultaneous Determination of Dexpanthenol, Lidocaine Hydrochloride, Mepyramine Maleate and their Related Substances by a RP-HPLC Method in Topical Dosage Forms.

The pharmaceutical combination of dexpanthenol (DPA), lidocaine hydrochloride (LIH) and mepyramine maleate (MAM) is used for their anti-allergic, anti-inflammatory, anti-pruritic, anesthetic and antiseptic properties. The present study was aimed to develop and validate a new, first and rapid high performance liquid chromatographic method for simultaneous determination of DPA, LIH and MAM in the presence of their stress-induced degradation products in pharmaceutical gel/fluigel formulations. The chromatographic separation was performed on an Inertsil ODS-3 V, 250 × 4.6 mm (5 µm) column using a gradient mobile phase of an aqueous solution of ammonium acetate (0.01 M) and methanol mixture at gradient flow rates of 1.3 mL/min and 1.5 mL/min with detection at 230 nm. The retention times for DPA, LIH and MAM were ~3.28 min, 11.67 min and 12.99 min, respectively. The method was validated in accordance with International Conference on Harmonisation guidelines. Calibration curves were linear in the ranges of 9-54 µg/mL for MAM and LIH and 30-180 µg/mL for DPA with satisfactory correlation coefficients (R2 > 0.999). The mean % recoveries obtained were found to be 99.9% for MAM, 100.3% for LIH and 99.3% for DPA. Precision % RSD was <2. Robustness results were uniform, there were no marked changes, so method is highly validated. All drugs were subjected to stress conditions and degradation products were separated with acceptable peak tailing (T ≤ 2) and good resolution (Rs > 2). The validated method therefore can be adapted for quality control procedures of the drugs in pharmaceutical dosage forms and their stability studies.

Comparison of East and West Survival Nomograms in Turkish Gastric Cancer Patients Who Underwent Radical Surgery.

BACKGROUND AND AIM:: The clinicopathological demonstrations of gastric cancer vary widely between Eastern and Western countries. Turkey is situated in Europe and Middle East which acts as a bridge between east and west. We aimed to validate the two popular nomograms of east and west origin by means of patients who underwent curative surgery for gastric cancer in our country. MATERIAL AND METHODS:: Of the 202 patients diagnosed with gastric cancer between the years 2006 and 2013, 145 of these patients whose data were sufficient were included in the study. For all patients, demographic, laboratory, operative, and pathologic findings were documented. For each patient, prognostic factors were incorporated into the nomograms for estimating 5-year survival probability. RESULTS:: For a Turkish cohort, the western nomogram showed a better discriminative capacity (AUC = 0.721, 95% confidence interval 0.637-0.806) and was better calibrated (the Hosmer-Lemeshow goodness-of-fit test p = 0.323), as compared to the eastern nomogram with AUC = 0.615, 95% confidence interval 0.522-0.708, and p = 0.077, respectively. CONCLUSION:: Western nomogram was found to be more effective than eastern nomogram in prediction of estimating 5-year survival probability in patients with resectable gastric cancer in Turkish population.

Fade or fate. Seroma in laparoscopic inguinal hernia repair.

BACKGROUND: Postoperative fluid collection in the space left behind the dissected hernia sac in laparoscopic herniorraphy puts the surgeon in a dilemma as to whether it is a recurrence or a seroma, and it is not always easily judged only by physical examination (PE). Another important issue is what kind of seroma can be accepted as a complication of surgery. METHODS: Thirty patients with unilateral inguinal hernia who had a hernia sac of >4 cm were operated on with transabdominal preperitoneal hernia repair (TAPP) technique and the collection at the hernia site was followed by PE and superficial ultrasonography (USG) postoperatively on the first day, first week, first month, and third month. RESULTS: USG detected seroma in 20 patients, while 17 could be noticed by PE on the first postoperative day. At the end of the third month, seromas resolved by 90%, and could only be detected by USG in two patients. Pain or complication rates attributable to seroma in patients were not determined (p > 0.05) in the statistical analyses between the groups. CONCLUSIONS: Superficial USG is a beneficial tool in differentiating early recurrence or seroma in patients. It should not be intervened with as a complication until the patient has complaints attributable to seroma.

Calcium level may be a predictive factor for pseudocyst formation after acute pancreatitis.

Pancreatic pseudocysts (PPs) are defined as fluid collections more than 4 weeks old that are surrounded by a nonepithelial wall of fibrous or granulation tissue. Many risk factors have been associated with pseudocyst development but predictive factors remain to be explored. The aim of this study was to investigate the clinical, and biochemical parameters that may predict the development of a PPs after an attack of acute pancreatitis (AP). The medical charts of 102 patients diagnosed with AP were enrolled into the study. Demographic, clinical and laboratory details were recorded at admission and at the 48(th) hour. There were several risk factors on admission and at the 48(th) hour that was predictive of PP formation when evaluated by univariate analysis such as: Alanine aminotransferase level at 48 hrs, calcium level at admission, base excess at 48 hrs, calcium level at 48 hrs, and albumin level at 48 hrs. In multivariate analysis, low calcium level at admission was the only variable that was shown to predict formation of PPs. Lower serum calcium level may be a predictive factor for the development of PPs after AP attack. We advise that patients with calcium levels below 8 mg/dl, after AP should be followed more closely.

Coexistence of life threatening chemotherapy related leukoencephalopathy, saggital sinus thrombosis and multiple organ failure in a child with acute lymphoblastic leukemia: an unusual case with clinical recovery.

A nine-year old girl with T cell acute lymphoblastic leukemia (ALL) had acute severe neurologic complications at the end of the remission-induction chemotherapy course. Thirty-six hours following triple intrathecal (IT) therapy and intravenous (IV) administration of L-asparaginase (L-asp), tetraplegia developed and she became unconscious. She had bouts of hypertension and persistent tachycardia unresponsive to digitalis therapy. Magnetic resonance imaging (MRI) showed multiple brain white matter hyperintensities and filling defects in the saggital sinus, suggesting thrombosis. Over the 40 days, in addition to her neurologic compromise she also had transient diabetes mellitus, severe hyperlipidemia, hypoproteinemia and edema, liver and heart failure and staphylococcus aureus sepsis with prolonged bone marrow depression. Despite, coexistence of all these chemotherapy related complications, her neurologic functions and multiple organ failure improved gradually. After a 70 days' period of interruption, chemotherapy was resumed and continued without any further complications. Although, the etiology of her extensive sensitivity to some drugs remains unclear, we believe that it is important to document these unusual events in this child.

Can metformin reduce insulin resistance in polycystic ovary syndrome?

OBJECTIVE: To examine whether metformin is able to reduce insulin resistance in polycystic ovary syndrome (PCOS). DESIGN: Single-blind study comprising two successive periods of treatment: 8 weeks of placebo and 10 weeks of metformin (orally, 850 mg twice daily). SETTING: Clinic of endocrinology and metabolism of Cerrahpasa Medical Faculty at Istanbul University, Istanbul, Turkey. PATIENTS: Sixteen insulin-resistant women with PCOS. INTERVENTIONS: Insulin sensitivity (with an IV insulin tolerance test), plasma glucose and insulin levels during an oral glucose tolerance test (OGTT), serum androgens, and lipids were measured at baseline and after each treatment period. RESULTS: Insulin sensitivity, the mean fasting serum levels of glucose, insulin, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total T, free T, androstenedione, DHEAS, and LH:FSH ratio, and the areas under the curve for plasma glucose and insulin during OGTT were not changed by either placebo or metformin treatment. CONCLUSION: Metformin does not decrease insulin resistance in PCOS. This finding suggests that cellular mechanism of insulin resistance in PCOS is different from other common insulin-resistant states such as non-insulin dependent diabetes mellitus and obesity.

An unusual complication of extracorporeal shock wave lithotripsy: urinoma due to rupture of the renal pelvis.

A case of a female patient with urinoma due to rupture of the renal pelvis after extracorporeal shock wave lithotripsy is described. Although temporary perirenal fluid accumulations after extracorporeal shock wave lithotripsy have been reported previously, possibly this is the first case presenting with an abdominal mass due to retroperitoneal urine collection.

An in vivo study on the effect of scaffold geometry and growth factor release on the healing of bone defects.

The hypothesis of this study was that the extent of bone regeneration could be enhanced by using scaffolds with appropriate geometry, and that such an effect could be further increased by mimicking the natural timing of appearance of bone morphogenetic proteins BMP-2 and BMP-7 after fracture. Bioplotted poly(ε-caprolactone) (PCL) disks with four different fibre organizations were used to study the effect of 3D scaffold architecture on the healing of bone defects in a rat pelvis model. Moreover, one PCL construct was further modified by introducing a nanoparticulate sequential BMP-2/BMP-7 delivery system into this scaffold. Scaffolds and functionalized construct along with free nanocapsules were implanted using a rat iliac crest defect model. Six weeks post-implantation, the defects were evaluated by CT scan and histology. Analysis revealed that the basic architecture, having the highest pore volume for tissue ingrowth, presented the highest bone formation as determined by the bone mineral density (BMD) within the defect (144.2 ± 7.1); about four-fold higher than that of the empty defect (34.9 ± 10.7). It also showed the highest histological analysis scores with a high amount of bone formation within the defect, within the scaffold pores and along the outer surfaces of the scaffold. The basic scaffold carrying the BMP-2/BMP-7 delivery system showed significantly higher bone formation than the growth factor-free basic scaffold at 6 weeks (BMD 206.8 ± 15.7). Histological analysis also revealed new bone formation in close to or in direct contact with the construct interface. This study indicates the importance of open and interconnecting pore geometry on the better healing of bone defects, and that this effect could be further increased by supplying growth factors, as is the case in nature.

DNA damage, DNA susceptibility to oxidation and glutathione level in women with polycystic ovary syndrome.

Recent studies have addressed the possibility of an association between polycystic ovaries and ovarian cancer. DNA damage is the first step of the carcinogenesis, and susceptibility to cancer, in general, is characterized by high DNA damage. Free radical-mediated DNA damage and impaired antioxidant defence have been implicated as contributory factors for the development of cancer. This study evaluates DNA damage (strand breakage, base oxidation, formamidopyrimidine DNA glycosylase (Fpg) sensitive sites), H2O2-induced DNA damage, a marker of DNA susceptibility to oxidation and glutathione (GSH) level, a powerful antioxidant, in women with polycystic ovary syndrome (PCOS). Women with PCOS showed a significant decrease in GSH level, a significant increase in DNA strand breakage and H2O2-induced DNA damage. Although Fpg-sensitive sites were higher in the PCOS group compared to the control group, the difference did not reach a statistically significant level. Significant correlations were found between free testosterone and DNA strand breakage (r = 0.46, p<0.01) and free testosterone and H2O2-induced DNA damage (r = 0.41, p<0.05). The data indicate that DNA damage and susceptibility of DNA to oxidative stress are increased in women with PCOS and may explain the association between PCOS and ovarian cancer.

Delayed neurological symptoms from the spontaneous migration of a bullet in the lumbosacral spinal canal. Case report.

In a patient wounded by a gunshot in the abdomen, the bullet was radiologically located intradurally at S1 level. Although she had no neurological deficit at admission, she developed pain and motor weakness a few days later. At operation the bullet was found at L4 level and its removal resulted in complete neurological recovery.

Determination of tibial torsion by computed tomography.

Torsional malalignment of the lower extremity, especially during childhood, is a common concern and even an anxiety to the parents. Torsional deformity may be seen at one or more sites, and tibial torsion is a frequent cause of this problem. Medial femoral torsion and metatarsus adductus also affects the alignment of the extremity. Although a corrective osteotomy for tibial torsion is performed very rarely, the precise determination is mandatory. Tibial torsion and the torsion of the leg was measured in 25 adults by computed tomography. The inclination between the dorsal tangent to the tibial condyles and the distal reference line was considered as tibial torsion. The distal reference line was formed with intersection of centers of medial and lateral malleoli. While measuring the torsion of the leg, tangent dorsal to the femoral condyles was used for proximal reference line. In the females, the average of tibial torsion was 31.07 degrees for the right side and 30.02 degrees for the left. For the males, the averages were 32.7 and 35.26 degrees for the right and left sides, respectively.

Does Helicobacter pylori-induced gastritis enhance food-stimulated insulin release?

The fact that H. pylori gastritis results in an increased secretion of basal and meal-stimulated gastrin, which is also a physiologic amplifier of insulin release directed us to investigate whether H. pylori gastritis may lead to an enhancement of nutrient-stimulated insulin secretion. For this purpose, we have investigated the insulin responses to both oral glucose and a mixed meal in 15 patients with H. pylori gastritis before and one month after the eradication therapy and also in 15 H. pylori-negative control subjects. The areas under the curve (AUC) for serum insulin following both oral glucose and a mixed meal in the patients with H. pylori gastritis before the eradication were significantly (P < 0.05) higher than those in the H. pylori-negative controls. After the eradication of H. pylori, the AUC for serum insulin following oral glucose and mixed meal decreased by 9.4% and 13.1%, respectively (P < 0.001 in both), and serum basal and meal-stimulated gastrin levels decreased significantly (P < 0.001). These results suggest that H. pylori gastritis enhances glucose and meal-stimulated insulin release probably by increasing gastrin secretion.