Self-assembled hierarchical nanostructures composed of novel chalcopyrite nanosheets for photovoltaic properties

Self-assembled nanostructures of CulnGaSe2 (CIGS) comprising of nanosheets with sheet thickness of 20 nm have been developed via one-step electrochemically alloying technique. These self-assembled nanoplates exhibit highly intersecting behavior and transform from CuSe to CIGS as the reduction potential was varied. The morphological analysis indicated that the process resulted in a progression of crystallites to a series of heavy dense intersecting nanoplates. Further analyses revealed that the nanostructures keep their integrity on heat treatment. The structure confirms the inclusion of Indium and Gallium at higher reduction potentials and its transition from pseudoamorphous to polycrystalline structure. A strong correlation between reduction potential, and the composition was established. The spectroscopic and optical spectra clearly prove that the direct band gap for the as-grown and annealed thin films, and appropriate for solar cell applications. These self-assembled dense interweaved nanoplates structure have not been observed previously in CIGS semiconductor system and have potential implications forenergy applications.

Identification of differentially expressed genes in breast cancer

A number of genes differentially expressed in breast cancer were isolated using a subtractive cloning technique. DNA sequence analysis and GenBank searches of T4F10, T2H7, and T2E5 cDNA clones found them to be identical with E2A, MSS1, and SEC13R genes. Their expression in a variety of primary breast tumor and cancer cell lines was compared with c-ERB-B2 and pS2 by Northern blot analysis. In breast cancer cell lines, the genes that we isolated are more frequently expressed than the previously described c-ERB-B2 and pS2.

Photoluminescence Investigation of Surface Oxidation of C0.9Zn0.1 Te Detectors

The effect of surface oxidation of Cd1−xZnxTe (x = 0.1) detectors by chemical etching in hydrogen peroxide aqueous solution (H2O2) at different concentrations and etching times was investigated by low temperature photoluminescence (PL). The treatment resulted in better surface condition evidenced by the larger I(D0, X)/Idef intensity ratio and the narrower full width at half maximum of the main peak (D0, X). Peak shifts in the PL spectra associated with bound exciton lines and free to bound transition were also observed and attributed to the oxide layer. These surface effects were found to be dependent on H2O2 concentration and etching time. The significance of this surface oxidation on device passivation and the subsequent improvements in the detector performance are also discussed.

Prospects for High Energy Resolution Gamma Ray Spectroscopy with Europium-Doped Strontium Iodide

Europium-doped strontium iodide scintillators offer a light yield exceeding 100,000 photons/MeV and excellent light yield proportionality, while at the same time, SrI2 is readily grown in single crystal form. Thus far, our collaboration has demonstrated an energy resolution with strontium iodide of 2.6% at 662 keV and 7.6% at 60 keV, and we have grown single crystals surpassing 30 cm3 in size (with lower resolution). Our analysis indicates that SrI2(Eu) has the potential to offer 2% energy resolution at 662 keV with optimized material, optics, and read-out. In particular, improvements in feedstock purity may result in crystal structural and chemical homogeneity, leading to improved light yield uniformity throughout the crystal volume, and consequently, better energy resolution. Uniform, efficient light collection and detection, is also required to achieve the best energy resolution with a SrI2(Eu) scintillator device.

Bare below elbows: does this policy affect handwashing efficacy and reduce bacterial colonisation?

INTRODUCTION

UK Department of Health guidelines recommend that clinical staff are 'bare below the elbows'. There is a paucity of evidence to support this policy. One may hypothesise that absence of clothing around wrists facilitates more effective handwashing: this study aims to establish whether dress code affects bacterial colonisation before and after handwashing.

SUBJECTS AND METHODS

Sixty-six clinical staff volunteered to take part in the study, noting whether they were bare below the elbows (BBE) or not bare (NB). Using a standardised technique, imprints of left and right fingers, palms, wrists and forearms were taken onto mini agar plates. Imprints were repeated after handwashing. After incubation, colonies per plate were counted, and subcultures taken.

RESULTS

Thirty-eight staff were BBE and 28 were not. A total of 1112 plates were cultured. Before handwashing there was no significant difference in number of colonies between BBE and NB groups (Mann-Whitney, P < 0.05). Handwashing reduced the colony count, with greatest effect on fingers, palms and dominant wrists (t-test, P < 0.05). Comparing the two groups again after handwashing revealed no significant difference (Mann-Whitney, P < 0.05). Subcultures revealed predominantly skin flora.

CONCLUSIONS

There was a large variation in number of colonies cultured. Handwashing resulted in a statistically significant reduction in colony count on fingers, palms and dominant wrist regardless of clothing. We conclude that handwashing produces a significant reduction in number of bacterial colonies on staff hands, and that clothing that is not BBE does not impede this reduction.

Invasive lobular carcinoma of the breast: should this be regarded as a chronic disease?

BACKGROUND

The surgical treatment of patients with invasive lobular carcinoma is still controversial due to its different clinical and pathological features. Most studies report local recurrence after relatively short follow-up periods, which is usually 5 years. However there is some evidence to suggest that local recurrence may occur late in the course of follow-up.

AIM OF THE STUDY

To study the implications and outcome of extending the follow-up period of patients treated for invasive lobular carcinoma.

PATIENTS AND METHODS

Patients (268) treated between 1989 and 1996 were reviewed. Thirty-three patients were excluded as they had primary hormonal therapy. The outcomes for 235 patients were analyzed.

RESULTS

Seventy-nine patients (33.6%) had breast conservation surgery (group I), which was followed by re-excision due to positive margins in 23 patients (29%), and 156 patients (66.3%) had mastectomy (group II). Compared to group II, tumours in group I were smaller (mean size 17 vs. 37 mm, P=0.001), multifocal [20 (25%) vs. 14 (9%), P=0.003] and with more positive margins [23 (29%) vs. 24 (15%), P=0.0009]. Only 33 patients (21%) in group II, and all patients in group I had post-operative radiotherapy (P=0.0001). Forty-eight patients (17.9%) developed local recurrence [27 (34%) in group I and 21 (13.4%) in group II, P=0.0005] after a median follow-up period of 167.8 months. The mean time to local recurrence was 127 (range 24-196) months. Univariate analysis showed that the type of surgery, margin status, adjuvant radiotherapy and chemotherapy significantly affected local recurrence (P=0.0005, 0.02, 0.04 and 0.05 respectively). Cox regression analysis showed that the only factor affected local recurrence was the type of surgery (relative risk 2.43, 95% confidence interval 1.22-4.83, P=0.01) The overall survival was 99.3 months (78.2%). Univariate and Cox regression analyses showed that only the patients age at diagnosis significantly affected survival (P=0.003).

CONCLUSION

Local recurrence may be a late event in patients treated for invasive lobular carcinoma of the breast and extended follow-up may be considered. In this study mastectomy offers better local control.

Phase I study combining an IGFR inhibitor (IMC-A12) and an mTOR inhibitor (temsirolimus) in patients with solid tumors or lymphoma

e14535

Background: IMC-A12 is a fully humanized IgG1/ lambda monoclonal antibody directed at the type I Insulin-Like Growth Factor Receptor (IGF-IR). Temsirolimus, an ester of the macrocyclic immunosuppressive agent sirolimus, is a cytostatic cell cycle inhibitor, which specifically inhibits the mammalian target of rapamycin (mTOR). A paradoxical increase in AKT activation by an mTOR inhibitor through an IGF-1R-dependent mechanism may compromise the therapeutic effect of mTOR inhibitors. Hence we evaluated the combination of temsirolimus and IMC-A12. Methods: This standard “3+3” design used a fixed dose of 25 mg IV weekly of temsirolimus with an escalating weekly dose of IV IMC-A12 at 3 mg/kg, 4 mg/kg and 6 mg/kg with no intrapatient dose escalation. The goal of this study is to define the MTD and to evaluate the biologic effects and metabolic activity of IMC-A12 and temsirolimus, individually and in combination. Patients with advanced solid tumors and lymphoma are eligible. No history of diabetes is allowed in dose escalation cohorts. Results: To date, 11 patients (4 males and 7 females, median age 47) with various solid tumor histologies have been enrolled across 3 dose cohorts with the current dose cohort at 6 mg/kg weekly IV of IMC-A12 and 25 mg weekly IV of temsirolimus. The MTD has not been determined. The most common grade 1 and grade 2 toxicities have been dysgeusia (n=5), fatigue (n=5), hyperglycemia (n=6), hypertriglyceridemia (n=6), leucopenia (n=4), mucositis (n=4), and ocular flashes of light (n=3). No grade 3 or 4 toxicity lasted more than 7 days (nausea n=1; vomiting n=1; thrombocytopenia n=1). Two patients (metastatic prostate cancer and metastatic breast cancer) demonstrated prolonged stable disease for 4 and 6 months, respectively. Conclusions: Preliminary data suggest that the combination is well tolerated and that it warrants further investigation. The expansion phase of this study will evaluate the biologic effects and metabolic activity of IMC-A12 and temsirolimus, individually and in combination, through the use of RPPA (Reverse Phase Protein Assays) and PET scans.

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Divergent changes of serum 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine in patients with acute myocardial infarction

The serum levels of thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3',5'-triiodothyronine (reverse T3, rT3), thyroxine-binding globulin and thyroid-stimulating hormone have been monitored in 13 patients with acute myocardial infarction. The major changes recorded were a transient decrease in T3 and a transient increase in rT3. They reached a nadir and a peak, respectively, within three days. A conceivable explanation for these alterations is that the monodeiodination of T4 is diverted from the activating pathway (T4 to T3) to the inactivating pathway (T4 to rT3).

Effects of dexamethasone, desoxycorticosterone, and ACTH on serum concentrations of thyroxine, 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine

The effects of a pure glucocorticoid, dexamethasone, and a pure mineralocorticoid, desoxycorticosterone, on the serum concentrations of thyroxine (T4), 3,5,3'-triiodothyronine (T3), and 3,3',5'-triiodothyronine (reverse T3, rT3) were compared both in healthy subjects and in athyreotic T4-substituted patients. In addition, the effect of exogenous ACTH was examined in healthy subjects. Both in healthy subjects and in T4-substituted athyreotic patients, administration of a single oral dose of dexamethasone caused a rapid and sharp decrease in the serum concentration of T3, and a corresponding increase in the serum concentration of rT3. The T4 concentration was not changed. A single oral dose of desoxycorticosterone evoked no significant changes in the serum concentrations of T3, rT3, or T4 either in healthy subjects or in T4-substituted athyreotic patients. Like dexamethasone, ACTH (two i.v. injections of 60 IU each, at a 6-hour interval) evoked a serum T3 reduction and a serum rT3 increase. Hence, it appears that both endogenous and exogenous glucocorticoids, but not mineralocorticoids, may partially divert the deiodination of T4 from the activating (T4 lead to T3) to the inactivating (T4 leads to rT3) pathway.

Blood levels of 3,5,3'-triiodothyronine and thyroxine: differences between children, adults, and elderly subjects

The serum levels of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) in children, adolescents, adults, and elderly subjects have been measured by radioimmunoassays. It was found that while the T4 levels were essentially equal in all age groups examined, the T3 levels were markedly different. In children and adolescents (1-15 years), high values were recorded; indeed, they exceeded the upper normal limit in adults (20-80 years). From the age of 20, the T3 levels remained unaltered until the age of 80, after which there was a further reduction, to values approaching the lower normal limit for T3 in middle-aged subjects. The findings emphasize that separate normal values must be established for different age groups, in order to avoid diagnostic misinterpretations and therapeutic failures.

Surface plasmon resonance in CdSe semiconductor coated with gold nanoparticles

We have grown CdSe semiconductor films on glass substrates and the films were coated with Au nanoparticles of 10 nm in size by the pulsed-laser deposition technique. The films demonstrate a large enhancement of Raman intensity and photoluminescence of CdSe semiconductor via excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaics, and related devices, including biosensors.