Genetic diversity studies based on morpho-pathological and molecular variability of the Sclerotinia sclerotiorum population infecting potato (Solanum tuberosum L.).

White mould or stem rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is a devastating fungal disease found in major potato cultivation areas worldwide. The aim of this study was to characterize genetic diversity in the S. sclerotiorum population from the main potato producing regions of India by means of morphological (mycelial growth, colony colour, number and distribution pattern of sclerotia) and molecular characteristics, as well as to evaluate the virulence of S. sclerotiorum isolates in potato for the first time. Among the S. sclerotiorum population analyzed, high phenotypic and genotypic diversity were observed. Using all the morphological characteristics, a dendrogram was constructed based on Gower's similarity coefficient that distributed all the isolates into three clusters at the 0.62 similarity coefficient. Carpogenic germination of apothecia revealed that larger sclerotia produced a greater number of apothecia while smaller sclerotia produced fewer apothecia. Pathogenicity test results revealed that out of 25 isolates, seven were highly aggressive, 14 were moderate and four had low aggressiveness, whilst isolates from Punjab were more pathogenic than those of Uttar Pradesh. Phylogenetic analysis of universal rice primer polymorphism showed high genetic variability within the isolates that grouped all the isolates in three evolutionary lineages in the resulting dendrogram and showed partial relationship with geographical locations of the isolates. Further, the findings suggest the occurrence of higher heterogeneity and genetic diversity among the S. sclerotiorum isolates that indicates the existence of both clonal and sexual reproduction in the pathogen population of potato producing areas in India.

Genome sequence and analysis of the tuber crop potato.

Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.

Voice outcomes after thyroidectomy without superior and recurrent laryngeal nerve injury: VoiSS questionnaire and GRBAS tool assessment.

Voice symptoms are frequently reported early after thyroidectomy, even in the absence of laryngeal nerves injury. We evaluated the short-term outcomes of these functional alterations. Thirty-nine patients were enrolled in a prospective observational trial, evaluating voice function before and 3 months after uncomplicated thyroidectomy, using VoiSS as assessed using a validated patient rated questionnaire; and perceptual voice analysis using GRBAS scale (Grade, Roughness, Breathiness, Asthenia, Strain). Impact of dysphonia on patient's life using VoiSS questionnaire revealed differences between pre- and postoperative assessment. There was statistically significant worsening in the impairment subgroup of VoiSS (p = 0.027). GRBAS evaluation was consistent between the three independent raters but showed differences between pre- and postoperative voice assessment. Age, TSH and a preoperative finding of laryngopharyngeal reflux significantly predicted quality of voice after thyroid surgery (all p < 0.004), as identified by the GRBAS assessment tool, but not type of surgery, gender or smoking status; although prediction of total variance in changes of voice was modest (r 2 = 0.07). Voice changes may occur after thyroidectomy without evident laryngeal nerve injury. Patients should be made aware of possible mild changes in voice even after uncomplicated thyroid surgery and this might be considered to be part of the informed consent.

Expression of microRNA-155 correlates positively with the expression of Toll-like receptor 7 and modulates hepatitis B virus via C/EBP-ß in hepatocytes.

Effective recognition of viral infection and successive activation of antiviral innate immune responses are vital for host antiviral defence, which largely depends on multiple regulators, including Toll-like receptors (TLRs) and microRNAs. Several early reports suggest that specific TLR-mediated immune responses can control hepatitis B virus (HBV) replication and express differentially with disease outcome. Considering the versatile function of miR-155 in the TLR-mediated innate immune response, we aimed to study the association between miR-155 and TLRs and their subsequent impact on HBV replication using both a HBV-replicating stable cell line (HepG2.2.15) and HBV-infected liver biopsy and serum samples. Our results showed that miR-155 was suppressed during HBV infection and a subsequent positive correlation of miR-155 with TLR7 activation was noted. Further, ectopic expression of miR-155 in vitro reduced HBV load as evidenced from reduced viral DNA, mRNA and subsequently reduced level of secreted viral antigens (HBsAg and HBeAg). Our results further suggested that CCAAT/enhancer-binding protein-ß (C/EBP-ß), a positive regulator of HBV transcription, was inhibited by miR-155. Taken together, our study established a correlation between miR-155 and TLR7 during HBV infection and also demonstrated in vitro that increased miR-155 level could help to reduce HBV viral load by targeting C/EBP-ß.

Two Dimensional Effective Electron Mass at the Fermi Level in Quantum Wells of III-V, Ternary and Quaternary Semiconductors.

In this paper we study the influence of strong electric field on the two dimensional (2D)effective electron mass (EEM) at the Fermi level in quantum wells of III-V, ternary and quaternary semiconductors within the framework of k x p formalism by formulating a new 2D electron energy spectrum. It appears taking quantum wells of InSb, InAs, Hg(1-x)Cd(x)Te and In(1-x)Ga(x)As(1-y)P(y) lattice matched to InP as examples that the EEM increases with decreasing film thickness, increasing electric field and increases with increasing surface electron concentration exhibiting spikey oscillations because of the crossing over of the Fermi level by the quantized level in quantum wells and the quantized oscillation occurs when the Fermi energy touches the sub-band energy. The electric field makes the mass quantum number dependent and the oscillatory mass introduces quantum number dependent mass anisotropy in addition to energy. The EEM increases with decreasing alloy composition where the variations are totally band structure dependent. Under certain limiting conditions all the results for all the cases get simplified into the well-known parabolic energy bands and thus confirming the compatibility test. The content of this paper finds three applications in the fields of nano-science and technology.

Serum fetuin-A concentration predicts glycaemic outcomes in people with prediabetes: a prospective study from eastern India.

AIM: To evaluate the role of fetuin-A levels in predicting glycaemic outcomes (progression to diabetes or reversion to normoglycaemia) in people with prediabetes. METHODS: A total of 2119 people were screened, of whom 144 people with prediabetes, 50 people with normoglycaemia and 66 people with newly diagnosed diabetes underwent estimation of fasting insulin, fetuin-A, interleukin-6, interleukin-1ß, tumour necrosis factor-α, lipid and 25-hydroxyvitamin-D levels and assessment of non-alcoholic fatty liver disease using ultrasonography and the fatty liver index. People with prediabetes were followed and analysed according to glycaemic outcome and quartile of fetuin-A level. RESULTS: Fetuin-A, interleukin-1ß, interleukin-6, tumour necrosis factor-α and triglyceride levels and presence of non-alcoholic fatty liver disease increased across the glycaemic spectrum and were highest in people with diabetes. A total of 32 people with prediabetes reverted to normoglycaemia, 23 progressed to diabetes and 65 remained with prediabetes over a mean ± sd follow-up of 32.12 ± 8.4 months. People progressing to diabetes had higher baseline glycaemia rates, fetuin-A levels, interleukin-1ß levels, fatty liver index scores and prevalence of non-alcoholic fatty liver disease and lower 25-hydroxyvitamin-D levels. People with prediabetes in the highest fetuin-A quartile had the highest risk of progression to diabetes (relative risk 2.68, 95% CI 0.95-7.55; P = 0.06) and the lowest rate of reversion to normoglycaemia (relative risk 0.27, 95% CI 0.08-0.85; P = 0.03). Fetuin-A levels correlated with interleukin-1ß levels (r = 0.420; P < 0.001), interleukin-6 levels (r = 0.231; P = 0.022) and fatty liver index scores (r = 0.319; P < 0.001). Cox regression showed that higher fetuin-A levels and higher BMI and lower 25-hydroxyvitamin-D levels were predictive of lower rates of reversion to normoglycaemia. Age, triglyceride levels, and interleukin-6 and interleukin-1ß levels were predictive of progression to diabetes. CONCLUSIONS: Increased fetuin-A level has an adverse impact on glycaemic outcomes in prediabetes. This study highlights the importance of fetuin-A as a predictor of glycaemic outcomes in prediabetes.

Leiomyoma of broad ligament mimicking ovarian malignancy- report of a unique case.

Tumors of the broad ligament are uncommon. Leiomyoma, which is the commonest female genital neoplasm, is also the most common solid tumor of the broad ligament. Leiomyomas affect 30% of all women of reproductive age but the incidence of broad-ligament leiomyoma is <1%. These benign tumors are usually asymptomatic. A case is being described where a 52 year old presented with gradual abdominal swelling which was clinically and radiologically diagnosed as ovarian malignancy. On abdominal and bimanual palpation a soft cystic mass was noted in the right pelvic region. CA 125 was mildly raised. CEA, CA 19.9 levels were within normal limit. The radiological diagnosis was ovarian cyst with possibility of malignant changes. Staging laparotomy and histopathological examination of the resected specimen revealed a right sided broad ligament leiomyoma with cystic changes. The degenerative changes in the leiomyoma lead to the clinical and radiological diagnostic confusion. Thus, though uncommon, broad ligament leiomyoma should be considered during evaluation of adnexal masses for optimal patient management. The above description of leiomyoma in the broad ligament is a highly unique case and thus deserves appropriate attention.

Down-conversion luminescence nanocomposites based on nitrogen-doped carbon quantum dots@bioplastic for applications in optical displays, LEDs and UVC tubes.

Carbon quantum dots (CQDs)-based composites as luminous down-conversion materials are becoming more popular due to several advantages such as steady fluorescence, ease of functionalization, tailoring of emission in the visible range, and so on. We report an inexpensive and environmentally sustainable synthesis of fluorescent nitrogen doped-CQDs produced from Cissus quadrangularis, a low-cost plant precursor with therapeutic value. The morphological, structural, and physicochemical features of the material were carefully investigated. Under UV stimulation (365 nm), almost spherical shaped N-CQDs with an average diameter of 5.1 nm were discovered to generate yellow-green fluorescence, have excellent photostability, and strong water solubility, with a quantum yield of up to 5 %. Furthermore, as a solid-phase dispersion matrix for CQDs, ecologically friendly and biodegradable bioplastic is appealing. The down-conversion of solid-state fluorescence of LEDs and UVC tubes was demonstrated by creating a nanocomposite by inserting N-CQDs into the solid matrix of a wheat starch-based bioplastic. Furthermore, employing constructed quantum dot-based optical displays, down-converted LEDs, and UVC tubes, the impacts of varied CQD concentrations and pH sensitivity were examined.

Production and function of IL-12 in islets and beta cells.

AIMS/HYPOTHESIS: IL-12 is an important cytokine in early inflammatory responses and is implicated in the immune-mediated pathogenesis of pancreatic islets in diabetes. However, little is known about the direct effects of IL-12 on islets and beta cells. METHODS: In this study, beta cell function, gene expression and protein production were assessed in primary human donor islets and murine beta cell lines in response to stimulation with IL-12 or a pro-inflammatory cytokine cocktail (TNF-α, IL-1ß and IFN-γ). RESULTS: The pro-inflammatory cytokine cocktail induced islet dysfunction and potently increased the expression and production of IL-12 ligand and IL-12 receptor in human islets. In human islets, the receptor for IL-12 co-localised to the cell surface of insulin-producing cells. Both IL-12 ligand and IL-12 receptor are expressed in the homogeneous beta cell line INS-1. IL-12 induced changes in gene expression, including a dose-dependent upregulation of IFNγ (also known as IFNG), in INS-1 cells. A neutralising antibody to IL-12 directly inhibited IFNγ gene expression in human donor islets induced by either IL-12 or pro-inflammatory cytokine stimulation. Functionally, IL-12 impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cells and human donor islets. A neutralising antibody to IL-12 reversed the beta cell dysfunction (uncoupling of GSIS or induction of caspase-3 activity) induced by pro-inflammatory cytokines. CONCLUSIONS/INTERPRETATION: These data identify beta cells as a local source of IL-12 ligand and suggest a direct role of IL-12 in mediating beta cell pathology.

Evaluation of anti-infective potential of a tribal folklore Odina wodier Roxb against some selected microbes and herpes simplex virus associated with skin infection.

AIM: To evaluate the in vitro antimicrobial activity of aqueous and methanol extracts of Odina wodier bark (OWB), a folk medicine, against representative bacteria, fungi and herpes simplex virus (HSV) associated with skin infections. METHODS AND RESULTS: The OWB extract(s) was found to inhibit the isolates of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli at an MIC of 256-5000 µg ml(-1) and Candida albicans at and above 4000 µg ml(-1) by agar and broth dilution assays. The growth curve of Staph. aureus revealed the highest activity within 2-6 h of methanol extract (ME) exposure. Interestingly, the MTT and plaque reduction assay showed that the extracts can inhibit HSV-1 and HSV-2 at EC50 of 22·4 and 28·8 µg ml(-1) , with Selectivity index of 11·7-15. While the time kinetic and binding assays demonstrated that the ME at 50 µg ml(-1) prevents viral attachment into Vero cells. Phytochemical and HPLC analysis of ME revealed the presence of flavonoids, phytosterols, saponins and tannins including the pseudotannin chlorogenic acid. CONCLUSION: The traditional use of OWB for the management of skin infections has scientific basis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated the antimicrobial potential of OWB on selected isolates of bacteria, fungi and HSV, associated with skin infections.

Histomorphometry of feline chronic kidney disease and correlation with markers of renal dysfunction.

Chronic kidney disease is common in geriatric cats, but most cases have nonspecific renal lesions, and few studies have correlated these lesions with clinicopathological markers of renal dysfunction. The aim of this study was to identify the lesions best correlated with renal function and likely mediators of disease progression in cats with chronic kidney disease. Cats were recruited through 2 first-opinion practices between 1992 and 2010. When postmortem examinations were authorized, renal tissues were preserved in formalin. Sections were evaluated by a pathologist masked to all clinicopathological data. They were scored semiquantitatively for the severity of glomerulosclerosis, interstitial inflammation, and fibrosis. Glomerular volume was measured using image analysis; the percentage of glomeruli that were obsolescent was recorded. Sections were assessed for hyperplastic arteriolosclerosis and tubular mineralization. Kidneys from 80 cats with plasma biochemical data from the last 2 months of life were included in the study. Multivariable linear regression (P < .05) was used to assess the association of lesions with clinicopathological data obtained close to death. Interstitial fibrosis was the lesion best correlated with the severity of azotemia, hyperphosphatemia, and anemia. Proteinuria was associated with interstitial fibrosis and glomerular hypertrophy, whereas higher time-averaged systolic blood pressure was associated with glomerulosclerosis and hyperplastic arteriolosclerosis.

Risk factors for delirium and inpatient mortality with delirium.

BACKGROUND: There is limited on the risk factors and mortality in patients with delirium from India. AIM: This study aimed to evaluate the risk factors associated with delirium and inpatient mortality rates of patients diagnosed with delirium by psychiatry consultation liaison services. MATERIALS AND METHODS: Three hundred and thirty-one patients diagnosed as delirium by the psychiatry consultation liaison services were examined on standardized instruments: Delirium Rating Scale Revised 98 version (DRS-R-98), amended Delirium Motor Symptom Scale (DMSS), Delirium Etiology Checklist (DEC), Charlson Comorbidity index, and a checklist for assessment of risk factors. RESULTS: More than three medications as a risk factor and metabolic/endocrine disturbances as cause were observed to play largest role in development of delirium. The inpatient mortality rate was 12.4%. Compared to the survivor group, those who died were more likely to be young (<65 years), had significantly high rate of alcohol dependence and were more frequently restrained prior to development of delirium; of these only age <65 years and use of restraints emerged as the significant predictors of mortality in regression analysis. CONCLUSION: Age and use of restraints appears to be an important predictor mortality in patients with delirium.

Development and application of reverse transcription-loop mediated isothermal amplification assay for sensitive detection of groundnut bud necrosis virus infecting potato.

Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detection of groundnut bud necrosis virus (GBNV) causing potato stem necrosis disease. The isothermal temperatures, reaction periods and concentrations of reaction mixture were optimized where, the assay worked well at 65 °C for 50 min, 6 U of WarmStart Bst 2.0 DNA polymerase, 1.4 mM dNTPs and 2.0 mM MgSO4. The optimized assay proved to be specific to GBNV with no cross reactivity to other viruses infecting potato in India. The specificity of RT-LAMP assay was found to be 100 fold more sensitive than that of RT-PCR. The developed assay was applied for the detection of GBNV from 80 potato leaf samples where 24 samples were found infected which was confirmed by RT-PCR. It was concluded that the RT-LAMP assay developed for detection of GBNV was specific, sensitive and suitable for its use in virus indexing under potato seed production programme.

Detection of prodromal symptoms of relapse in mania and unipolar depression by relatives and patients.

BACKGROUND & OBJECTIVES: Detection of prodromal symptoms among patients with mania by their immediate relatives has been seldom examined. We carried out this study to examine the ability to detect and report prodromol symptoms of manic relapses by patients themselves and their relatives. METHODS: The ability of patients and their relatives to detect prodromal symptoms was examined among 60 remitted patients, 30 each with DSM-IV diagnoses of bipolar disorder and recurrent depressive disorder, with recent manic/depressive relapses, and their 60 immediate relatives, using an instrument composed of items from common symptom-scales, as well as by unstructured interview. RESULTS: Seventy per cent of patients with mania reported prodromes prior to relapse. This was significantly (P<0.01) less than the proportion of their relatives (97%), as well as the proportion of patients with unipolar depression (93%), reporting prodromal symptoms (P<0.05) among patients. Mean duration of the prodromal period reported by patients with mania was about 20 days (median-10 days); relatives reported durations which were longer by about 5 days. Prodromes of unipolar depression (mean 42.7 days; median- 21 days), were significantly longer than of mania, when reported by patients, but not by their relatives. Differences in reporting of prodromes, between relatives and patients seen in mania, were not observed in unipolar depression. The number and type of prodromal symptoms of mania reported was similar among patients and relatives. INTERPRETATION & CONCLUSIONS: Our findings showed that relatives of patients with mania were better at detecting prodromes of relapse; thus, input from relatives can improve the early detection of prodromal symptoms to prevent relapses of bipolar disorder.

Knowledge, experience & attitudes concerning electroconvulsive therapy among patients & their relatives.

BACKGROUND & OBJECTIVES: Electroconvulsive therapy (ECT) is used frequently in developing countries, but investigations of patients' awareness and perception of ECT are rare. The present study thus attempted a comprehensive examination of knowledge, experience and attitudes concerning ECT among patients treated with brief-pulse, bilateral, modified ECT, and their relatives. METHODS: Of the 153 recipients of ECT, 77 patients and relatives were eventually assessed using questionnaires designed to evaluate their awareness and views about ECT. RESULTS: Patients were middle-aged, poorly-educated, often unemployed, with chronic, severe, and predominantly psychotic illnesses. Relatives were mainly parents, older, better-educated and usually employed. Apart from the very rudimentary aspects, patients were largely unaware of the procedure. Though most did not find the experience of ECT upsetting, sizeable proportions expressed dissatisfaction with aspects such as informed consent, fear of treatment and memory impairment. Although patients were mostly positive about ECT, ambivalent attitudes were also common, but clearly negative views were rare. Relatives were significantly likely to be more aware, more satisfied with the experience and have more favourable attitudes towards ECT, than patients. INTERPRETATION & CONCLUSIONS: The results endorse the notion that recipients of ECT are generally well-disposed towards the treatment, but also indicate areas where practice of ECT needs to be improved to enhance satisfaction among patients and relatives.

Occult HBV infection among anti-HBc positive HIV-infected patients in apex referral centre, Eastern India.

BACKGROUND: The prevalence of occult HBV, defined by the presence of HBV DNA in individuals with antibodies to HBV core antigen and with absence of HBV surface antigen, but its clinical significance and virological features in HIV-infected patients is still unclear. AIM: To investigate the prevalence, clinical significance and molecular characterization of occult hepatitis B virus infection in ART-Naive HIV-positive individuals. MATERIAL AND METHODS: Among the 1077 HIV-infected patients with different risk factors for HIV infection, 297 were HBsAg-ve ART-naive, of them 112 was randomly selected for the study. HBV DNA was tested by in-house PCR and quantified by qPCR. Molecular characterization was performed by sequencing the envelope and overlapping polymerase genes. RESULTS: We found the prevalence of occult HBV to be 10.7% among a randomly selected group of HBsAg-ve/antiHBc+ve HIV-infected patients. Overall 33.9% (38 of 112) of the patients were antiHBc positive indicating exposure to HBV infection. HBV DNA was detected in 12/38 (31.5%) antiHBc positive samples and 50% of them had CD4 T cell count < 200 cells/mm(3). HCV coinfection was low (2.7%). No surrogate marker for OBI could be identified. Presence of antiHBs antibodies did not rule out OBI. Liver biopsy in six cases showed varying stages of chronic hepatitis. Several mutations were detected but not the common immune escape mutant G145R. CONCLUSION: In conclusion the prevalence of OBI was significantly high among HIV coinfected patients, which highlights the importance of HBV DNA testing in these patients and indicates need for further prospective studies in larger cohorts to assess its clinical significance.

Influence of drying of biosludge on organochlorine compounds from pulp and paper industry.

Pulp and paper industry is one of the major sources of man-made generation of organochlorine compounds. During biological treatment of wastewater, part of organochlorine compounds is discharged with treated effluent and part is retained on biomass and disposed of as waste activated sludge. Due to presence of these compounds, the disposal of biosludge from pulp and paper industry has become an issue. The estimation of adsorbable organic halogen (AOX) compounds after drying and grinding resulted in 49% lower concentration of AOX due to stripping of purgeable compounds. These purgeable compounds are not released at 60 degrees C in aqueous medium during estimation of purgeable organic halogen (POX) compounds. Dispersion of sludge by sonication overcomes the loss of POX compounds and results in higher concentration ofAOX compounds. The drying of biosludge samples at 45, 100 degrees C and in presence of sun light resulted in 20.1, 49.0 and 29.6% removal of purgeable AOX compounds, respectively. The lab scale sorption study using dichloromethane (as volatile organochlorine compound) reveal that biosludge from pulp and paper industry is a good adsorbent of volatile organochlorine compounds and results in poor release of these compounds during estimation of POX compounds.

Spraying of dsRNA molecules derived from Phytophthora infestans, along with nanoclay carriers as a proof of concept for developing novel protection strategy for potato late blight.

BACKGROUND: Phytophthora infestans is a late blight-causing oomycetes pathogen. It rapidly evolves and adapts to the host background and new fungicide molecules within a few years of their release, most likely because of the predominance of transposable elements in its genome. Frequent applications of fungicides cause environmental concerns. Here, we developed target-specific RNA interference (RNAi)-based molecules, along with nanoclay carriers, that when sprayed on plants are capable of effectively reducing late blight infection. RESULTS: Targeted the genes unique to sporulation, early satge infection and the metabolism pathway stages based on in an our own microarray data. We used nanoclay as a carrier for sorbitol dehydrogenase, heat shock protein 90, translation elongation factor 1-α, phospholipase-D like 3 and glycosylphosphatidylinositol-anchored acidic serine-threonine-rich HAM34-like protein double-stranded (ds)RNAs, which were assessed by culture bioassay, detached leaf assay and spray methods, and revealed a reduction in growth, sporulation and symptom expression. Plants sprayed with multigene targeted dsRNA-nanoclay showed enhanced disease resistance (4% disease severity) and less sporulation (<1 × 103 ) compared with plants sprayed with dsRNA alone. CONCLUSION: The use of nanoclay with multigene targeted dsRNA was assumed to be involved in effective delivery, protection and boosting the action of RNAi as a spray-induced gene silencing approach (SIGS). A significant reduction in growth, sporulation, disease severity and decreased gene expression authenticates the effects of SIGS on late blight progression. This study demonstrated as a proof of concept the dsRNA-nanoclay SIGS approach, which could be used as an alternative to chemical fungicides and transgenic approaches to develop an environmentally friendly novel plant protection strategy for late blight. © 2022 Society of Chemical Industry.

Thermal stability of the peak emission wavelength in multilayer InAs/GaAs QDs capped with a combination capping of InAlGaAs and GaAs.

The effect of rapid thermal annealing (RTA) on the optical properties of a 10 layer stacked InAs/GaAs quantum dot (QD) heterostructure where the QDs are overgrown with a combination of quaternary InAlGaAs and GaAs capping have been investigated. TEM micrographs showed that the shape of the QDs is preserved for annealing temperatures up to 800 degrees C. The peak emission wavelength of the investigated heterostructures remains stable on annealing at temperatures upto 750 degrees C, which is unusual in QD samples. This phenomenon is attributed due to the suppression of the strain-enhanced intermixing in such structures. One of the reasons behind such suppression is the strain driven phase separation of Indium from the overgrown quaternary alloy, which maintains an In rich region across the QD periphery thereby checking the out-diffusion of Indium from the dots. The overlapping vertical strain from the under lying dot layers in the QD stack also maintains a strain relaxed state at the QD base, thereby preventing the material mixing at the base of the pyramidal QDs. This stability of wavelength is of paramount importance in optoelectronic devices where the design is based on the emission wavelength of the active region.

Degradation of pentachlorophenol by Kocuria sp. CL2 isolated from secondary sludge of pulp and paper mill.

A pentachlorophenol (PCP) degrading bacterium was isolated and characterized from sludge of pulp and paper mill. This isolate used PCP as its sole source of carbon and energy and was capable of degrading this compound, as indicated by stoichiometric release of chloride and biomass formation. Based on morphology, biochemical tests, and 16S rRNA gene sequence analysis this strain was identified as Kocuria sp. CL2. High Performance Liquid Chromatography (HPLC) analysis revealed that this strain was able to degrade PCP up to a concentration of 600 mg/l. This is first time we are reporting the degradation of PCP by the Kocuria species. This isolate was also able to remove 58.64% of PCP from the sludge within two weeks. This study showed that the removal efficiency of PCP by CL2 was found to be very effective and can be used in degradation of PCP containing pulp paper mill waste in the environment.