Hybrid dielectric light trapping designs for thin-film CdZnTe/Si tandem cells.

Tandem solar cells consisting of high bandgap cadmium telluride alloys atop crystalline silicon have potential for high efficiencies exceeding the Shockley-Queisser limit. However, experimental results have fallen well below this goal significantly because of non-ideal current matching and light trapping. In this work, we simulate cadmium zinc telluride (CZT) and crystalline silicon (c-Si) tandems as an exemplary system to show the role that a hybrid light trapping and bandgap engineering approach can play in improving performance and lowering materials costs for tandem solar cells incorporating crystalline silicon. This work consists of two steps. First, we optimize absorption in the crystalline silicon layer with front pyramidal texturing and asymmetric dielectric back gratings, which results in 121% absorption enhancement from a planar structure. Then, using this pre-optimized light trapping scheme, we model the dispersion of the CdxZn1-xTe alloys, and then adjust the bandgap to realize the best current matching for a range of CZT thicknesses. Using experimental parameters, the corresponding maximum efficiency is predicted to be 16.08 % for a total tandem cell thickness of only 2.2 µm.

Age- and sex-specific association of circulating osteocalcin with dynamic measures of glucose homeostasis.

SUMMARY: Our study showed that serum osteocalcin levels are closely related to glucose metabolism in men of all ages and younger women. This association disappeared in postmenopausal women in which increases bone turnover rates. The association between serum osteocalcin levels and glucose homeostasis should be interpreted according to age and sex. INTRODUCTION: Osteocalcin, a marker of bone formation, appears to be associated with glucose homeostasis. We investigated the age- and sex-specific association of serum osteocalcin level with variables related to glucose metabolism. METHODS: This study was based on cross-sectional analysis from 719 participants aged 20-85 years after excluding patients taking antidiabetic or antiosteoporotic drugs. The subjects were divided into four groups according to age and sex as follows: men <50 years (n = 131), men ≥50 years (n = 191), women <50 years (n = 108), and women ≥50 years (n = 279). Anthropometric and biochemical variables including insulin resistance (HOMA-IR) and ß cell function (HOMA-ß) from a 75-g oral glucose tolerance test, and serum 25-OH-vitamin D and parathyroid hormone levels were measured. RESULTS: The serum osteocalcin level was significantly higher in women aged ≥50 years compared with women <50 years (20.4 ± 7.8 vs. 17.9 ± 6.8 ng/ml, p < 0.001), but there was no difference between men aged ≥50 years and men <50 years (16.4 ± 5.9 vs. 16.8 ± 6.0 ng/ml, p = 0.905). The participants diagnosed with diabetes had lower serum osteocalcin levels than normal or prediabetic participants. Multivariable regression analyses including HOMA-IR and HOMA-ß indicated that serum osteocalcin levels had a negative and independent association with HbA1c levels in men and women aged <50 years, but not in women ≥50 years. CONCLUSIONS: Low osteocalcin levels are associated with impaired glucose metabolism in men and premenopausal women. The osteocalcin levels may be determined by factors related to bone metabolism in postmenopausal women. Our data suggest that the serum levels of osteocalcin associated with glucose homeostasis should be interpreted according to age and sex.

Three-dimensional efficient dispersive alternating-direction-implicit finite-difference time-domain algorithm using a quadratic complex rational function.

Efficient unconditionally stable FDTD method is developed for the electromagnetic analysis of dispersive media. Toward this purpose, a quadratic complex rational function (QCRF) dispersion model is applied to the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method. The 3-D update equations of QCRF-ADI-FDTD are derived using Maxwell's curl equations and the constitutive relation. The periodic boundary condition of QCRF-ADI-FDTD is discussed in detail. A 3-D numerical example shows that the time-step size can be increased by the proposed QCRF-ADI-FDTD beyond the Courant-Friedrich-Levy (CFL) number, without numerical instability. It is observed that, for refined computational cells, the computational time of QCRF-ADI-FDTD is reduced to 28.08 % of QCRF-FDTD, while the L2 relative error norm of a field distribution is 6.92 %.

Time domain simulation of tandem silicon solar cells with optimal textured light trapping enabled by the quadratic complex rational function.

Amorphous silicon/crystalline silicon (a-Si/c-Si) micromorph tandem cells, with best confirmed efficiency of 12.3%, have yet to fully approach their theoretical performance limits. In this work, we consider a strategy for improving the light trapping and charge collection of a-Si/c-Si micromorph tandem cells using random texturing with adjustable short-range correlations and long-range periodicity. In order to consider the full-spectrum absorption of a-Si and c-Si, a novel dispersion model known as a quadratic complex rational function (QCRF) is applied to photovoltaic materials (e.g., a-Si, c-Si and silver). It has the advantage of accurately modeling experimental semiconductor dielectric values over the entire relevant solar bandwidth from 300-1000 nm in a single simulation. This wide-band dispersion model is then used to model a silicon tandem cell stack (ITO/a-Si:H/c-Si:H/silver), as two parameters are varied: maximum texturing height h and correlation parameter f. Even without any other light trapping methods, our front texturing method demonstrates 12.37% stabilized cell efficiency and 12.79 mA/cm² in a 2 µm-thick active layer.

Pro-inflammatory mediators and signaling proteins in the decidua of pre-eclampsia.

OBJECTIVE: To evaluate the role of CD68+ macrophages and inflammatory/signaling proteins in the decidua of singleton pregnancies with late-onset pre-eclampsia. PATIENTS AND METHODS: This study was designed as a prospective case-control study. Decidual tissue samples were obtained from twenty healthy pregnant women as a control group and twenty pregnant women with late-onset pre-eclampsia showing severe symptoms as the study group. We examined the abundance of CD68+ macrophages in both groups using flow cytometry. Protein and mRNA expression levels of inflammatory/signaling proteins, including inducible nitric oxide synthase, nuclear factor-κB inhibitor α, cyclooxygenase-2, and phosphorylated c-Jun N-terminal kinase, in the decidua of both groups were measured using Western blotting and Reverse Transcription-Polymerase Chain Reaction, respectively. Student's t-tests were performed for statistical analysis. RESULTS: The numbers of CD68+ macrophages were similar in the study and control groups (p=0.47). However, the levels of inducible nitric oxide synthase, nuclear factor-κB, cyclooxygenase-2, and phosphorylated c-Jun N-terminal kinase were significantly increased in the study group. Therefore, pro-inflammatory mediators and signaling proteins in the decidua during pre-eclampsia may be related to the pathogenesis of pre-eclampsia. CONCLUSIONS: Pre-eclampsia-induced alterations in the expression of inflammatory/signaling proteins in the decidua during singleton pregnancies may play a critical role in the pathogenesis of pre-eclampsia.

Chip- and board-level optical interconnections using rigid flexible optical electrical printed circuit boards.

A new optical interconnection scheme based on a rigid flexible optical electrical printed circuit board (RFOE-PCB) is suggested. The easily installed RFOE-PCB can be universally applied for both chip- and board-level optical interconnections. This letter describes the detailed fabrication process, optical properties, and heat-resisting property of the RFOE-PCB. The fabricated RFOE-PCB was also successfully demonstrated with a 2.5-Gb/s data transmission through a 45 degrees-ended optical waveguide embedded in the RFOE-PCB.

Analysis of efficacy and safety of core-needle biopsy versus fine-needle aspiration cytology in patients with cervical lymphadenopathy and salivary gland tumour.

In this study, we compared the diagnostic accuracy and safety of fine-needle aspiration cytology and core-needle biopsy in patients with cervical lymphadenopathy or salivary gland tumour, and provided a basis for selecting the appropriate diagnostic method in clinical situations. A total of 278 patients were included in this study. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 66.7% and 100%, respectively, and negative predictive values were 92.6% and 100%, respectively, for diagnosing malignancy. In diagnosing lymphoma, fine-needle aspiration cytology gave false-negative results in all patients. In diagnosing tuberculous lymphadenopathy, the sensitivities of fine-needle aspiration cytology and core-needle biopsy were 33.3% and 91.15%, respectively, and the negative predictive values were 90.0% and 95.1%, respectively. The sensitivities of fine-needle aspiration cytology and core-needle biopsy were 42.9% and 100% in diagnosing malignant salivary gland tumours, and the negative predictive values were 91% and 100%, respectively. The results of this study showed that core-needle biopsy was superior in diagnosing and distinguishing critical diseases such as malignant lymphadenopathy and tuberculosis in patients with cervical lymphadenopathy and salivary gland tumour.

Identification of new minimally lost regions on 18q in head and neck squamous cell carcinoma.

Loss of heterozygosity (LOH) on 18q predicts poor survival in head and neck squamous cell carcinomas (HNSCCs). Several putative tumor suppressor genes, such as DCC, DPC4/Smad4, and MADR2/Smad2, are mapped to 18q, but thus far, the important gene locus in HNSCC is not known. To identify possible gene loci on 18q, we performed LOH studies using tumor DNA from 57 HNSCC primary tumor cell lines and DNA isolated from fibroblasts or lymphoblastoid cells from the same patients. Forty-two highly polymorphic microsatellite markers spaced not more than 5 cM apart (mean distance, 1.82 cM) spanning the region from D18S44 in 18q11.1 to D18S1141 in 18q23 were used. D18S71 in 18p11.21 on 18p was also used to determine whether the short arm was retained. Forty-three of 57 (75%) HNSCC lines showed LOH or isolated allelic imbalance (AI) for at least one locus on 18q. Although many of the cell lines had large distal 18q deletions with a breakpoint between 18q11.1 and 18q12.2 to qter, three loci were identified that were lost in 70% or more of the cases. The minimally lost regions (MLRs) range in size from 1.5-15.79 cM. The most proximal is centered on D18S39 (1.56 cM) in band 18q21.1, with LOH or isolated AI in 28 of 38 (74%) of informative cases. The largest (15.8 cM) begins at D18S61 (28 of 40; 70%) in band 18q22.2 and extends through D18S50 in 18q23. The third is centered on D18S70 (30 of 40; 75%) in band 18q23 (3.67 cM). Of these MLRs, only the one centered on D18S39 has been implicated previously in HNSCC. D18S70, the most frequently lost marker, was the only marker consistently lost in three tumor cell lines with very minimal losses, UM-SCC-19, UM-SCC-67, and UM-SCC-73A. In addition, UM-SCC-91 exhibited AI only at this locus, and UT-SCC-4 had AI at D18S70 and D18S39 only. Close physical mapping of these three regions may pinpoint one or more previously unidentified tumor suppressor genes.

Efficacy of ultrasound-guided core needle gun biopsy in diagnosing cervical lymphadenopathy.

OBJECTIVE: Ultrasound-guided fine needle aspiration cytology (US-FNA) is useful for diagnosing cervical lymphadenopathy. However, FNA, has a high false negative rate, especially in patients with lymphoma. Ultrasound-guided core needle gun biopsy (US-CNB) has recently become important for diagnosing cancers, but its value remains undetermined. This study evaluates the efficacy of US-CNB, performed in an outpatient setting, in diagnosing cervical lymphadenopathy and the spectrum of related diseases. MATERIALS AND METHODS: This retrospective study included 79 subjects who were not squamous cell carcinoma suspects and did not have a history of malignancy between January 2006 and July 2009. A US-CNB was performed on enlarged cervical lymph nodes (>1.0cm) in all subjects. Diagnostic sensitivity, specificity, and accuracy of US-CNB in differentiating between malignant and benign lymphadenopathy were evaluated. All enrolled subjects underwent a planned US-FNA before the study US-CNB was performed. Results of US-CNB and US-FNA were compared. RESULTS: The correct histopathological diagnoses were made in 73 of 79 subjects (91.1%) using US-CNB samples. Of these, the most common diagnoses were reactive hyperplasia (26 subjects), Kikuchi's disease (17 subjects), tuberculous lymphadenitis (15 subjects), lymphoma (8 subjects), and metastatic carcinoma (3 subjects). The US-CNB was very good at differentiating between malignant and benign lymphadenopathy, with a diagnostic sensitivity, specificity, and accuracy of 91.6%, 100%, and 98.6%, respectively. Additionally, US-CNB was more accurate than US-FNA in identifying lymphoma (88.8% vs. 11.1%) and Kikuchi's disease (89.4% vs. 29.4%). No US-CNB related-complications were observed. CONCLUSION: The US-CNB is safe, effective, and has a high diagnostic yield for cervical lymphadenopathy. The US-CNB may also be useful for diagnosing lymphoma and Kikuchi's disease.

Prognostic significance of tumour progression and human papillomavirus in advanced tonsillar cancer classified as stage IVa.

OBJECTIVE: To identify clinical factors that can explain the differences in treatment outcome, and examine the value of human papillomavirus infection as a prognostic biomarker in stage IVa tonsillar carcinomas. METHODS: Fifty-nine patients with tonsillar carcinoma classified as stage IVa were retrospectively analysed for survival outcomes according to various clinical factors. Human papillomavirus infection was evaluated using a human papillomavirus DNA chip test and immunohistochemical staining for p16 and p53. RESULTS: Lower disease-free survival rates were associated with increasing local invasiveness and nodal status. Although human papillomavirus positivity and p16 expression was more common in locally advanced tonsillar carcinomas with advanced nodal status, the overall survival rate was better for patients with human papillomavirus positive, p16-positive tumours. CONCLUSION: The disease-free survival rate may differ according to local tumour invasiveness and nodal status, even for stage IVa tonsillar cancers. Human papillomavirus infection may be a useful biomarker for predicting treatment outcomes for stage VIa tumours.

Age-related alteration of intracellular ATP maintenance in the cell suspensions of mice cerebral cortex.

Neurological alteration in the aging brain has been suggested to be due to, in part, a declined cellular energy metabolism. In order to understand age-related alteration of intracellular ATP maintenance, the present in vitro study measured change of intracellular adenosine triphosphate (ATP) content in cell suspensions of cerebral cortex isolated from male ICR mice aged 2 days (infant), 8 weeks (young adult) and 12 months (aged) under several different conditions, using the chemiluminescence technique. Among the three different ages, significant decrease of intracellular ATP content by oxygen deprivation for 15 min was observed in the cell suspensions of cerebral cortex from 12-month-old mice (P < 0.05). When cell suspensions of 8-week cerebral cortex were incubated with or without glucose (0-60 min), intracellular ATP content decreased in a time-dependent manner under both conditions, but depletion rate was significantly high in the glucose-free condition. This decrease was maximally restored by adding 1 mM glucose as tested. In addition, the ability for intracellular ATP maintenance in the presence or absence of glucose was age-dependently different. The rank order of difference of intracellular ATP content between with and without glucose was 3 months > 12 months > 2 days. The highest decrease of intracellular ATP content by incubation without glucose was observed in the 12-month samples. Sodium cyanide (100 microM) produced a gradual ATP depletion in cerebral cortex suspended from 2-day-old mice, but rapid change in both 8-week and 12-month samples. Combination of cyanide and iodoacetate (3.5 mM) rapidly depleted the intracellular ATP content in all age groups tested. These results suggest that the aging process in the cerebral cortex of mice is accompanied by alteration of maintenance of intracellular ATP homeostasis under a given condition, and this may be associated with pathological change of overall mechanisms involved in the development of neuronal disease in the senescent brain.

Caffeine causes glycerophosphorylcholine accumulation through ryanodine-inhibitable increase of cellular calcium and activation of phospholipase A2 in cultured MDCK cells.

Glycerophosphrylocholine (GPC) is a renal medullary compatible organic osmolyte that is derived from choline via phosphatidylcholine, which is catalyzed in part by phospholipase A2 (PLA2) and its degradation by GPC: choline phosphodiesterase (GPC: choline PDE). We found that caffeine elevated intracellular free calcium ([Ca2+]i) and GPC level in cultured MDCK cells, canine kidney epithelial cells, and propose a possible biochemical mechanism. When MDCK cells were incubated for 3 h with 1 to 10 mM caffeine, cellular GPC was elevated in a dose-dependent manner, and this occurred independently of the extracellular osmolality. Caffeine stimulated the rate of [14C]choline incorporation into [14C]GPC and PLA2 activity. Whereas, GPC: choline PDE activity was accompanied by less of increase. These enzyme changes demonstrate the increased net synthesis of MDCK GPC. In order to identify what triggers the PLA2 activation, [Ca2+]i was measured by using a fluorescence dye, Fura-2. Caffeine (10 mM) resulted in a typical transient increase in MDCK [Ca2+]i concentration, and this increase was greatly inhibited by pretreatment of MDCK cells with 10 mM ryanodine for 5 min. Ryanodine (10 mM) also inhibited the caffeine-induced stimulation of PLA2 activity. These findings provide the first evidence that caffeine in MDCK cells causes a ryanodine-inhibitable increase of [Ca2+]i and PLA2 activity, resulting in cellular GPC accumulation.

Mutagenicity in Salmonella and sister chromatid exchange in mice for 1,4-, 1,3-, 2,4-, and 3,4-dimethylphenanthrenes.

The mutagenicity in Salmonella and in vivo sister chromatid exchange in the bone-marrow cells of mice was determined for 1,4-, 1,3-, 2,4-, and 3,4-dimethylphenanthrene (DMPh) with the objective to study the relative importance of substitution at the 1 and 4 positions of this series of methylated phenanthrenes. For both tests, 1,4- DMPh was decidedly more genotoxic than the remaining regioisomers. While the well recognized role of steric crowding in the bay region is a factor in this enhanced genotoxicity, equally important is substitution at the 1 position with its potential to inhibit detoxication through 9,10-diol formation.

Triterpenoid saponins from the aerial parts of Lonicera japonica.

Two new triterpenoid saponins, loniceroside A and B, were isolated from the aerial parts of Lonicera japonica. Their structures were established as 3-O-alpha-L-arabinopyranosyl hederagenin 28-O-alpha-L-rhamnopyranosyl (1-->2)-[beta-D-xylopyranosyl(1-->6)]-beta-D-glucopyranosyl ester and 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl hederagenin 28-O-alpha-L-rhamnopyranosyl(1-->2)-[beta-D- xylopyranosyl(1-->6)]-beta-D-glucopyranosyl ester, respectively.

Anticomplementary activity of ginseng saponins and their degradation products.

The anticomplementary activity of ginseng saponins and their degradation products obtained by chemical treatment of Korean red ginseng saponins was investigated. The total saponin and its major components showed strong anticomplementary activity and their structure-activity relationship was evaluated.

Characterization of ochratoxin A transport by human organic anion transporters.

The purpose of this study was to investigate the characteristics of ochratoxin A (OTA) transport by multispecific human organic anion transporters (hOAT1 and hOAT3, respectively) using the second segment of proximal tubule (S2) cells from mice stably expressing hOAT1 and hOAT3 (S2 hOAT1 and S2 hOAT3). S2 hOAT1 and S2 hOAT3 exhibited a time- and dose-dependent, and a saturable increase in uptake of [3H]-OTA, with apparent Km values of 0.42 microM (hOAT1) and 0.75 microM (hOAT3). These OTA uptakes were inhibited by several substrates for the OATs. Para-aminohippuric acid (PAH), probenecid, piroxicam, octanoate and citrinin inhibited [3H]-OTA uptake by hOAT1 and hOAT3 in a competitive manner (Ki = 4.29-3080 microM), with the following order of potency: probenecid > octanoate > PAH > piroxicam > citrinin for hOAT1; probenecid > piroxicam > octanoate> citrinin > PAH for hOAT3. These results indicate that hOAT1, as well as hOAT3, mediates a high-affinity transport of OTA on the basolateral side of the proximal tubule, but hOAT1- and hOAT3-mediated OTA transport are differently influenced by the substrates for the OATs. These pharmacological characteristics of hOAT1 and hOAT3 may be significantly related with the events in the development of OTA-induced nephrotoxicity in the human kidney.

Guanidinoacetic acid (GAA) synthesis in rat tubular suspension as a system for evaluating gentamicin (GM) nephrotoxicity.

Since guanidinoacetic acid (GAA), a precursor of creatine, is synthesized mainly in the proximal tubule of the kidney where gentamicin (GM) nephrotoxicity often occurs, GM-induced renal cell damage was investigated using GAA synthesis in tubular suspension as an indicator. Results obtained were as follows: (1) GAA synthesis was significantly suppressed with 1 mM GM; (2) GM-induced decrease in GAA synthesis was recognized during incubation longer than 15 min; (3) furosemide significantly enhanced the suppression of GAA synthesis by GM. The results obtained parallel with those in the whole animal thus making GAA synthesis in tubular suspension a valid system for evaluating the GM-induced proximal tubular damage.

Radish extract stimulates motility of the intestine via the muscarinic receptors.

The effects of radish (Brassica oleraceae, Cruciferae) on gastrointestinal motility were examined using rat intestinal segments with myenteric plexus in-vitro and measuring the intestinal transit of charcoal in-vivo. Radish extract (10 microg mL(-1) to 2 mg mL(-1)) caused a dose-dependent increase in contractions of the duodenum, jejunum and ileum, and 1 mg mL(-1) was the maximum effective dose. The largest contraction by the extract was found in ileal segments. The extract-induced (0.5 mg mL(-1)) ileal contraction was remarkably inhibited by pretreatment of segments with atropine (10(-7) M) for 10 min, but not by hexamethonium (0.5 mM). Moreover, antagonists of the muscarinic receptor reduced the radish-induced ileal contraction by a different ratio. The rank order of inhibitory effects was 4-diphenylacetoxy-N-methyl-(2-chloroethyl)-piperidine methiodide (90.5% of control) > tropicamide (67.4%) > pirenzepine (42.8%) > methoctramine (16.7%). Oral administration of radish extract (300-500 mg kg(-1) body weight) to mice remarkably improved the intestinal transit of charcoal, and this was significantly attenuated by co-administration of atropine (50 mg kg(-1)). Taken together, these results suggest that radish extract stimulates gastrointestinal motility through activation of muscarinic pathways.

Shibimijihwang-tang elevates intracellular ATP and choline content in the cerebral cortex of ovariectomized rats.

Shibimijihwang-tang (SJT) has been used traditionally to improve systemic blood circulation and biological energy production in patients with circulatory and neuronal diseases. The object of this study is to determine the effect of SJT extract on the intracellular adenosine triphosphate (ATP) and choline content in the cerebral cortex of ovariectomized (OVX) rats. Bilateral ovaries of 8-week-old rats were removed. Rats were maintained for 12 weeks to deplete ovarian steroid hormones, followed by treatment with SJT at 500 mg/kg body weight per day for 12 weeks. High rate of body weight increase in the OVX rats was markedly reduced by treatment with SJT, but the change in body weight of normal rats was not affected by it. SJT also significantly reduced the decline of cerebral weight in the OVX rats (P<0.05). Tissue glucose content in the cerebral cortex of OVX rats was significantly increased by SJT treatment (P<0.05). A decline in cerebral ATP content in OVX rats was dramatically restored by SJT administration (P<0.01), but SJT did not change the cerebral ATP content in normal rats. Cerebral choline content also declined following ovariectomy. This reduction was significantly elevated by SJT treatment (P<0.05), but SJT did not affect the change in cerebral choline in normal rats. Taken together, these results demonstrate that SJT can reduce the decrease in brain weight, cerebral ATP and choline content caused by deprivation of ovarian steroid hormones. This suggests that pharmacological properties of SJT may play a role in improvement of reduced cerebral energy production and cholinergic neurotransmitter synthesis caused by deficiency of ovarian steroid hormones in the cerebroneuronal cells of postmenopausal women.