• Mycobiology
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• 제36권1호
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• pp.60-65
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• 2008

The effect of methanolic extract of cashewnut (Anacardium occidentale) shell extract was seen on conidial germination of Erysiphe pisi and powdery mildew development in pea (Pisum sativum). Maximum conidial germination inhibition of E. pisi on glass slides was observed at 300 ppm. Similar effect on floated pea leaves was observed after 48 h at the same concentration. Conidial germination on intact untreated pea leaves was also assessed on II and IV nodal leaves while IV and II nodal leaves were treated with the extract and vice versa. There was tremendous reduction in conidial germination on all the nodal leaves. The disease intensity of pea powdery mildew was significantly reduced by methanolic extract of cashewnut shells. Maximum reduction was observed with 200 ppm where 39% disease intensity was recorded in comparison to 96.53% in the control. The phenolic acid content of pea leaves following treatments with this extract varied and no defmite pattern was observed. Out of several phenolic compounds, namely, gallic, ferulic, chlorogenic, and cinnamic acids, only gallic acid was found to be present consistently in all the treatments with varied amounts.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.267-273
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• 2011

Methyl violet, used extensively in the commercial textile industry and as a biological stain, is a hazardous recalcitrant. Aspergillus sp. strain CB-TKL-1 isolated from a water sample from Tsumoriri Lake, Karzok, Ladakh, India, was found to completely decolorize methyl violet within 24 h when cultured under aerobic conditions at $25^{\circ}C$. The rate of decolorization was determined by monitoring the decrease in the absorbance maxima of the dye by UV-visible spectroscopy. The decolorization of methyl violet was optimal at pH 5.5 and $30^{\circ}C$ when agitated at 200 rpm. Addition of glucose or arabinose (2%) as a carbon source and sodium nitrate or soyapeptone (0.2%) as a nitrogen source enhanced the decolorization ability of the culture. Furthermore, the culture exhibited a maximum decolorization rate of methyl violet after 24 h when the C:N ratio was 10. Nine N-demethylated decolorized products of methyl violet were identified based on UV-visible spectroscopy, Fourier transform infrared (FTIR), and LC-MS analyses. The decolorization of methyl violet at the end of 24 h generated mono-, di-, tri-, tetra-, penta-, and hexa-N-demethylated intermediates of pararosaniline. The variation of the relative absorption peaks in the decolorized sample indicated a linear decrease of hexa-N-demethylated compounds to non-N-demethylated pararosaniline, indicating a stepwise N-demethylation in the decolorization process.

• Mycobiology
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• 제35권3호
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• pp.129-134
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• 2007

Systemic effect of two plant growth-promoting rhizobacterial (PGPR) strains, viz., Pseudomonas fluorescens (Pf4) and P. aeruginosa (Pag), was evaluated on pea (Pisum sativum) against the powdery mildew pathogen Erysiphe pisi. Foliar spray of the two PGPR strains was done on specific nodal leaves of pea and conidial germination of E. pisi was observed on other nodal leaves, distal to the treated ones. Conidial germination was reduced on distant leaves and at the same time, specific as well as total phenolic compounds increased in the leaves distal to those applied with PGPR strains, thereby indicating a positive correlation. The strains induced accumulation of phenolic compounds in pea leaves and the amount increased when such leaves were get inoculated with E. pisi conidia. Between the two strains, Pag was found to be more effective than Pf4 as its effect was more persistent in pea leaves. Foliar application of PGPR strains for the control of powdery mildew of pea is demonstrated in vitro while correlating it with the increased accumulation of plant phenolics.

• Advances in Energy Research
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• 제4권3호
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• pp.189-202
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• 2016

This work emphasized optimum production of biodiesel using non-edible Prunus armeniaca (Bitter Apricot) oil via transesterification collected from the high altitude areas of Himachal Pradesh, India. In this study the author produced biodiesel through the process of transesterification by using an alkali catalyst with alcohol (methanol and ethanol), under the varying molar ratio (1:6, 1:9, 1:12), variable catalyst percentage (1% and 2%) and temperature ($70^{\circ}C$, $75^{\circ}C$, $80^{\circ}C$, $85^{\circ}C$). Furthermore, a few strong base catalysts were used that includes sodium hydroxide, potassium hydroxide, sodium metal and freshly prepared sodium methoxide. After screening the catalyst, response surface methodology (RSM) in connection with the central composite design (CCD) was used to statistically evaluate and optimize the biodiesel production operation using NaOH as catalyst. It was found that the production of biodiesel achieved an optimum level biodiesel yield with 97.30% FAME conversion under the following reaction conditions: 1) Methanol/oil molar ratio: 1:6, 2) Reaction time: 3h, 3) Catalyst amount: NaOH 2 wt. %, and 4) Reaction temperature: $85^{\circ}C$. The experimental results showed that the optimum production and conversion of biodiesel through the process of transesterification could be achieved under an optimal set of reaction conditions. The biodiesel obtained showed appropriate fuel properties as specified in ASTM, BIS and En- standards.

• 대한토목학회논문집
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• 제13권3호
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• pp.93-105
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• 1993

본(本) 연구(硏究)에서 24개의 국부세굴공식(局部洗掘公式)을 이용(利用)하여 금강수계내(錦江水系內) 보청천(報靑川)에서의 교각설치(橋脚設置)에 따른 국부(局部) 세굴심도(洗掘深度)를 산정(算定)하여 서로 비교(比較) 하였는 바, 이때 24개의 국부세굴공식(局部洗掘公式)들은 무차원화(無次元化)된 공식(公式) 형태(形態)에 따라 6개의 그룹으로 구분(區分)되었다. 국부(局部) 세굴공식(洗掘公式) 적용자료(適用資料)로는 금강수계내(錦江水系內) IHP 대표측정지점(代表測定地點)인 산성, 이평, 산계 지점(地點)에 설치(設置)된 교량자료(橋梁資料)들과 실측(實測)된 하상자료(河床資料)들을 이용하였다. 하상자료(河床資料)들은 교량설치지점(橋梁設置地點)의 유향방향(流向方向)으로 좌안, 중앙부, 우안의 대표지점(代表地點)으로부터 시료(試料)를 채취(採取)하여 체가름 분석(分析)을 실시(實施)한 결과(結果)를 사용(使用)하였으며, 수리학적(水理學的) 자료(資料)로는 1982년(年)부터 1991년(年)까지 IHP 자료(資料)로 관측(觀測)된 최대(最大) 홍수위(洪水位) 및 최대(最大) 홍수위(洪水位)일때의 유속(流速)을 이용(利用)하였으며 교각자료(橋脚資料)들은 현장(現場)에서 실측(實測)된 자료(資料)를 이용(利用)하였다. 또한, 추후 보청천내(報靑川內) 교각(橋脚) 설치(設置)에 따른 국부(局部) 세굴(洗掘)을 검토(檢討)하기 위한 적절(適切)한 세굴공식(洗掘公式)을 제안(提案)하기 위하여 보청천(報靑川)과 흐름조건(條件)이 유사(類似)한 하천(河川)에서 실측(實測)된 129개의 국부세굴자료(局部洗掘資料)와 비교(比較)하였으며, 이를 통하여 Arunachalam 공식(公式), Shen-Karaki III 공식(公式), Jain-Fischer 공식(公式)이 보청천내(報靑川內) 세굴심도(洗掘深度) 산정(算定)을 위하여 비교적(比較的) 적절(適切)한 공식(公式)으로 판단(判斷)되었다. 또한 Inglis-Lacey 공식(公式)과 Shen-Karaki II 공식(公式)은 Fr의 수(數)가 0.3 이상인 비교적(比較的) 빠른 흐름에서 적용(適用)이 가능(可能)하며, Froehlich 공식(公式), Laursen I 공식(公式), Laursen II 공식(公式), Neill 공식(公式), Melville 공식등(公式等)은 Fr의 수(數)가 0.3 이하의 비교적(比較的) 느린 흐름에서 적용(適用)이 가능(可能)하고, Blench 공식(公式)이나 Inglis-Poona 공식(公式)은 Froude 수(數)에 따라 변화(變化)가 상당히 커서 적용(適用)하지 않는 것이 바람직한 것으로 판단(判斷)되었다. 또한 Sarma-Krishnamurthy 공식(公式), Ahmad 공식(公式), Coleman 공식(公式), Varzeliotis 공식(公式), Larras 공식(公式), Bata 공식(公式), Chitale 공식(公式), Venkatadri 공식(公式), Basik-Basamily-Ergun 공식(公式), U.S.G.S. 공식(公式), Shen I 공식(公式)들은 실측(實測)된 국부(局部) 세굴심도(洗掘深度)에 비하여 지나치게 적게 세굴심도(洗掘深度)를 산출(算出)하는 것으로 나타났다.

• Molecular & Cellular Toxicology
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• 제1권3호
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• pp.172-178
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• 2005

[ $21{\alpha}$ ]- and ${\beta}$-Methylmelianodiol were isolated as the inhibitor of IL-5 bioactivity from Poncirus tripoliata. To develope as an anti-septic drug, the genotoxicity of $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ was subjected to high throughput toxicity screening (HTTS) because they revealed strong IL-5 inhibitory activity and limitation of quantity. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of $21{\alpha}-methylmelianodiol$ was determined the concentration of $25.51\;{\mu}g/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. Also $21{\beta}-methylmelianodiol$ was determined the concentration of $24.15\;{\mu}g/mL\;and\;\;22.46\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, DNA damage was not observed both $21{\alpha}-methylmelianodiol\;and\;21{\beta}-methylmelianodiol$ in mouse lymphoma cell line. Also, the mutant frequencies in the treated cultures were similar to the vehicle controls, and none of $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ with and without S-9 doses induced a mutant frequency over. twice the background. It is suggests that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ are non-mutagenic in MOLY assay. The results of this battery of assays indicate that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ have no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$, as the optimal candidates with both no genotoxic potential and IL-5 inhibitory effects must be chosen.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1211-1216
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• 2004

A MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) induced chromium resistant strain ($Cr^{r}18$) of unicellular cyanobacterium Anacystis nidulans has been isolated and characterized. The resistant strain could grow (although restricted to $50\%$ of control) in chromium concentration (180${\mu}M$) lethal to the wild-type. Sublethal ($160{\mu}M$) concentration of $Cr^{6+}$ significantly reduced (13-$37.5$) all the photosynthetic pigments of A. nidulans with maximum reduction in phycoerythrin followed by ChI $\alpha$. Pigments of A. nidulans were drastically decreased in lethal concentration of Cr^{6+} with maximum reduction in phycoerythrin ($75\%$) and allophycocyanin ($67.5\%$). Resistant strain $Cr^{r}18$ resisted toxic effects of sublethal and lethal concentrations of $Cr^{6+}$ on photosynthetic pigments as revealed by less decrease in pigments as compared to A. nidulans. Effect of $Cr^{6+}$ stress was also studied on nitrogen assimilation and phosphate uptake. Sublethal concentration of $Cr^{6+}$ drastically reduced ($71.5\%$) nitrate uptake by A. nidulans while a decrease of $29\%$ was observed in strain $Cr^{r}18$. Short (2 day) exposure of A. nidulans and its resistant strain $Cr^{r}18\;to\;Cr^{6+}$ did not affect nitrate reductase and glutamine synthetase (transferase), whereas longer (10 day) exposure to $Cr^{6+}$ lowered activities of both enzymes in A. nidulans but not significantly in the strain $Cr^{r}18$. Ammonium uptake by both strains was not affected by $Cr^{6+}$. Thus, $Cr^{6+}$ affected photosynthetic pigments, nitrogen assimilation, and phosphate uptake of A. nidulans, while strain $Cr^{r}18$ was able to resist toxic effects of the metal. Advantages of using strain $Cr^{r}18$ for bioremediation purposes have been evaluated by studying $Cr^{6+}$ removal from the solution. Resistant strain $Cr^{r}18$ was able to remove $33\%$ more $Cr^{6+}$ than A. nidulans and thus it can prove to be a good candidate for bioremediation of $Cr^{6+}$ from polluted waters.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.571-582
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• 2020

Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 ㎍/ml. Sub-MIC concentrations (250 and 500 ㎍/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 ㎍/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 ㎍/ml) and 4-HPA (62.5 ㎍/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8227-8233
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• 2016

Background: To investigate polymorphisms in heat shock proteins A1B and A1L (HOM) and associated risk of oesophageal carcinoma in Northeast India. Materials and Methods: The study includes oesophageal cancer (ECA) patients attending general outpatient department (OPD) and endoscopic unit of Gauhati Medical College. Patients were diagnosed based on endoscopic and histopathological findings. Genomic DNA was typed for HSPA1B1267 and HSPA1L2437 SNPs using the polymerase chain reaction with restriction fragment length polymorphisms. Results: A total of 78 cases and 100 age-sex matched healthy controls were included in the study with a male: female ratio of 5:3 and a mean age of $61.4{\pm}8.5years$. Clinico-pathological evaluation showed 84% had squamous cell carcinoma and 16% were adenocarcinoma. Dysphagia grades 4 (43.5%) and 5 (37.1%) were observed by endoscopic and hispathological evaluation. The frequency of genomic variation of A1B from wild type A/A to heterozygous A/G and mutant G/G showed a positive association [chi sq=19.9, p=<0.05] and the allelic frequency also showed a significant correlation [chi sq=10.3, with cases vs. controls, OR=0.32, $p{\leq}0.05$]. The genomic variation of A1L from wild T/T to heterozygous T/C and mutant C/C were found positively associated [chi sq=7.02, p<0.05] with development of ECA. While analyzing the allelic frequency, there was no significant association [chi sq=3.19, OR=0.49, p=0.07]. Among all the risk factors, betel quid [OR=9.79, Chi square=35.0, p<0.05], tobacco [OR=2.95, chi square=10.6, p<0.05], smoking [OR=3.23, chi square=10.1, p<0.05] demonstrated significant differences between consumers vs. non consumers regarding EC development. Alcohol did not show any significant association [OR=1.34, chi square=0.69, p=0.4] independently. Conclusions: It can be concluded that the present study provides marked evidence that polymorphisms of HSP70 A1B and HSP70 A1L genes are associated with the development of ECA in a population in Northeast India, A1B having a stronger influence. Betel quid consumption was found to be a highly significant risk factor, followed by smoking and tobacco chewing. Although alcohol was not a potent risk factor independently, alcohol consumption along with tobacco, smoking and betel nut was found to contribute to development of ECA.

• 정보보호학회논문지
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• 제21권5호
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• pp.71-82
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• 2011

RFID 시스템은 여러 장점을 가지며 다양한 곳에서 이용되고 있다. 그러나 현재의 RFID 시스템은 무선통신과 저가 태그의 사용으로 인해 도청, 재전송 공격, 메시지 탈취, 태그에 대한 물리적 공격에 취약하다. 이런 공격들은 태그와 리더 사칭, 태그 무능화를 통한 서비스 거부공격, 태그 소지자의 위치 추적등을 유발한다. 이런 취약점을 해결하기 위해 다수의 RFID 인증 프로토콜이 제안되었다. 특히 Weis, Sarma, Rivest, Engels이 해시 기반 RFID 인증 프로토콜을 제안한 이래로, 많은 해시 기반 RFID 인증 프로토콜이 제안되었고 최근의 해시 기반 프로토콜은 보안성과 만족할 만한 수준의 프라이버시를 제공한다. 그러나 보안성과 만족할 만한 수준의 프라이버시를 제공하는 동시에 서버에서의 태그 인식 시간을 줄이는 것은 여전히 풀리지 않는 문제다. 이에 우리는 태그가 이전 통신 상태에 따라 응답 메시지를 생성하는 프로토콜을 제안한다. 그 결과 보안성과 프라이버시를 보장하는 동시에 서버에서 합리적인 시간안에 태그를 인식할 수 있다. 구체적으로 제안하는 프로토콜은 세션키와 롱텀 고정키를 모두 사용해서 이전 세션이 비정상 종료 된 경우에 비슷한 수준의 안전성을 제공하는 기존의 연구결과에 비해 태그 인식시간이 50%로 절감한 효과를 제공한다.