The Life and Times of Textualism in South Africa

This paper analyses the dominant approaches to statutory interpretation through a historical lens. It argues that for most of South Africa's history the methods of interpretation were twisted in order to give effect to the intentions of the legislature. This approach to interpretation has now been discarded into the waste bin of history, and intentionalism has been replaced with contextualism. Or so we are told. The judgment of the Supreme Court of Appeal in Natal Joint Municipal Pension Fund v Endumeni Municipality 2012 4 SA 593 (SCA) has been hailed as the new, settled approach to interpretation, with the Constitutional Court endorsing Endumeni on numerous occasions. But it appears from both the judgments of the Constitutional Court and those of other Courts that intentionalism is not yet dead. This paper argues that the reason for this is because Endumeni has not provided clarity to the process of interpretation that it proclaims to do. &nbsp

Fault Tolerance in Reversible Logic Circuits and Quantum Cost Optimization

Energy dissipation is a prominent factor for the very large scale integrated circuit (VLSI). The reversible logic-based circuit was capable to compute the logic without energy dissipation. Accordingly, reversible circuits are an emerging domain of research based on the low value of energy dissipation. At nano-level design, the critical factor in the logic computing paradigm is the fault. The proposed methodology of fault coverage is powerful for testability. In this article, we target three factors such as fault tolerance, fault coverage and fault detection in the reversible KMD Gates. Our analysis provides good evidence that the minimum test vector covers the 100 % fault coverage and 50 % fault tolerance in KMD Gate. Further, we show a comparison between the quantum equivalent and controlled V and V+ gate in all the types of KMD Gates. The proposed methodology mentions that after controlled V and V+ gate based ALU, divider and Vedic multiplier have a significant reduction in quantum cost. The comparative results of designs such as Vedic multiplier, division unit and ALU are obtained and they are analyzed showing significant improvement in quantum cost

不斉ヘテロ ディールス・アルダー反応に用いる新規有機分子触媒複合系の開発

医薬品をはじめとする多くの生物活性化合物は光学活性物質であり, その鏡像異性体は薬と毒のような，互いに異なる生体内作用を示すことが多い。そのため，有効な一方の鏡像異性体を高立体選択的に合成するための不斉合成反応の開発，特に不斉触媒を用いる触媒的不斉合成反応の開発は，新薬やキラル機能性分子を創製するために重要である。その不斉触媒の中で，金属を含有しない有機分子触媒は毒性が無く，空気中で安定であり取り扱いやすく安価であるなどの利点を有するため, 次世代の環境調和型触媒として現在活発な研究開発が行なわれている. 光学活性スピロインダノール類は，抗がん，抗 HIVや抗マラリヤ活性などの多彩な生物活性を示すことから，現在そのスピロインダノール骨格を構築するための有機合成反応の開発が活発に行われている。著者は，その合成反応として触媒的不斉ヘテロ ディールス・アルダー反応に着目し，その反応に有効な有機分子触媒複合系を開発することを目的として本研究を行った。著者は，有機分子触媒複合系として，β—アミノアルコールおよびβ—アミノシリルエーテルをそれぞれ触媒とし，アミノ酸を助触媒とするイサチン類とエノン類との不斉ヘテロ ディールス・アルダー反応を検討した。その結果，触媒としてはその分子中に第１級アミノ基や第１級水酸基，またシロキシ基をもつシンプルなキラルβ—アミノアルコールまたおよびβ—アミノシリルエーテルが，また助触媒としてはアミノ基に保護基したα—アミノ酸が本反応中で複合的に触媒活性機能を発現し，優れた化学収率とジアステレオ選択性およびエナンチオ選択性で目的のキラルイサチン誘導体が得られることが明らかとなった。本研究において著者は，光学活性スピロインダノール類の合成に有効な不斉ヘテロ ディールス・アルダー反応に用いる新規有機分子触媒複合系を開発することに成功した。開発した本触媒系は，他の創薬のために有用な不斉触媒反応においても触媒機能を示すことが期待され，さらに，本反応によって得られる光学活性スピロインダノール類は抗がん作用や他の様々な生物活性化合物の合成中間体としても有用であることから，本研究の成果は, 新薬創製を指向した合成開発研究に大きく貢献できると期待される.Many biologically active compounds, including pharmaceuticals, are optically active and often only one of the enantiomer shows a high biologically activity. Therefore, it is important to develop the synthetic methodology for providing only necessary enantiomer. As the methodology, catalytic asymmetric synthesis, in which the use of a low amount of a chiral catalyst theoretically enables infinite production of optically active compounds, is the most efficient in the synthetic organic chemistry field. Moreover, this methodology is also important in terms of energy saving and environmental friendliness. The chiral catalysts used in catalytic asymmetric syntheses can be divided into two categories of organometallic catalyst and metal-free organocatalyst. Particularly, organocatalyst is stable in air, nontoxic, easy to handle, and inexpensive, so they are being focused on as next-generation, environmentally friendly catalysts. Spirooxindoles are considered to be promising scaffolds in drug discovery. The structure of spirooxindoles is contained in many compounds having pharmacological activities such as contraceptive, anti-HIV, anticancer, antituberculosis, antimalarial, and antiproliferative drugs. Therefore, the development of an effective strategy for the preparation of highly optically pure spirooxindoles is a significantly challenging task in research. The hetero Diels–Alder (HDA) reaction is a versatile tool for effectively forming heterocyclic compounds. Especially, the catalytic asymmetric version of this reaction is the most efficient and convenient method for constructing a chiral heterocyclic skeleton, which acts as a precursor for many biologically active compounds and drugs. In this class of HDA reactions, the reaction of isatins with enones is one of the superior organic transformations for providing unique chiral spirooxindoles containing quaternary chiral carbon center on the structure. Author tried to explore new catalysts component system for this reaction using isatins as diene and enones as dienophile. As a result, author developed simple two catalysts component system consisting of primary β-amino alcohol or γ-amino silyl ether as catalysts and N-protected amino acid as a co-catalyst for the asymmetric HDA reaction of isatins with enones for the first time. These dual component systems showed efficient catalytic activities to afford the chiral spirooxindoles that are efficient synthetic intermediates for many biologically active compounds and drug discovery, in good to excellent chemical yields and with enough stereoselectivities. In this study, author revealed that the new explored catalysts component system showed excellent catalytic activity to the asymmetric HDA reaction of isatins with enones. It is expected that this results should be able to greatly contribute the development of new drugs and its related compounds.室蘭工業大学 (Muroran Institute of Technology)博士（工学）当アイテムは要旨のみの公開になっています（2021-6-23

Studies on the Effects of Bioprocess Parameters and Kinetics of Rhamnolipid Production by P. aeruginosa NITT 6L

Biosurfactants are gaining popularity in recent times due to lower toxicity, biodegradability, environmental compatibility and activity in extreme conditions. An air isolate was isolated previously for biosurfactant production in our laboratory, and characterized and named as P. aeruginosa NITT 6L. The biosurfactant thus produced was characterized to be surface-active rhamnolipid. This paper presents the study of the influence of various bioprocess parameters such as agitation, aeration and inoculum volume on rhamnolipid production by the isolate. Kinetics of rhamnolipid production in optimized media and process conditions were investigated. The rhamnolipid production was found to be increased after nitrogen depletion during stationary phase. The maximum rhamnolipid concentration of about 7.65 g L–1 was achieved after 96 h. Logistic model was found to be satisfactory in fitting the microbial growth. Emulsification activity of the crude rhamnolipid extract with different hydrocarbons was studied. The crude extract of rhamnolipid reduced the surface tension of water from 71.4 to 27.5 mN m–1, and CMC was about 11 mg L–1. Also, the usefulness of the extracted rhamnolipid produced under optimal conditions was investigated for remediation of crude oil contaminated soil. Soil washing with 0.3 % rhamnolipid removed about 71 % of crude oil present in sand samples within 24 h

세신과 폰가미아 유래 화합물들의 감수성 및 저항성 모기 종들에 대한 살충활성과 잠재적인 작용기작

학위논문 (박사)-- 서울대학교 대학원 : 농생물학과 곤충학 전공, 2012. 8. 안용준.모기는 전세계적으로 뎅그열, 황열, 말라리아 사상충증, 다양한 유형의 뇌염 등을 포함하는 열대•아열대성의 심각한 질병들을 매개하는 위생해충으로서 공중 위생보건분야에서 가장 중요하게 생각되고 있다. 모기유충의 방제를 위하여 유기인제, 프리메스린, 기타 살충제, 곤충 성장 조절제, 미생물살충제와 같은 살충제를 사용하고 있으나, 지속적이고 반복적인 사용으로 인하여 자연적인 생물학적 제어 시스템을 저해하고, 저항성 모기의 출현을 야기하였으며, 환경과 비대상 수서생물 및 인간의 건강에 문제가 나타남에 따라 대체 방제제의 탐색 및 개발이 요구되었다. 인간 삶과 질의 향상 그리고 환경문제의 해결을 위하여 기존에 사용되는 화학 살충제를 선택적 방제가 가능하고 자연상태에서 생분해되어 환경에 안전한 대안 살충제로의 대체가 진행되고 있으며, 이러한 대안 살충제는 대부분 식물에서 유래되고 있다. 따라서 현재 모기와 같은 해충의 제어를 위하여 친환경적이고, 비용에 있어서도 효율적인 식물 기반 제품의 사용이 불가피하게 요구된다. 현재 식물의 이차대사산물을 이용하는 제품과 같은 식물체 유래 제품은 잠재적으로 해충방제관리의 대체제로 새롭게 주목을 받고 있다. 본 연구에서는 세신(Asarum heterotropoides) 근경 정유와 메탄올 추출물의 구성성분 독성평가와 인도 식물 Millettia pinnata (L.) Panigrahi (formerly known as Pongamia pinnata)의 종자 유래 물질을 4종의 모기 유충에 대해 각각 생물검정을 실시하였다. 또한 분리된 활성물질을 동정하고, 가능한 메커니즘에 관하여 조사하였다. 세신 근경 정유 화합물의 3종의 모기 빨간집모기(Culex pipiens pallens), 에집트숲모기(Aedes aegypti), 토고숲모기(Ochlerotatus togoi) 3령 유충에 대한 독성을 직접-접촉 생물검정법을 이용하여 실시하였다. 결과는 fenthion과 temephos로 비교하였다. 세신 뿌리 정유는 반수치사농도(LC50) 기준으로 (LC50, 21.07–27.64 ppm)의 좋은 활성을 나타내었다. 높은 독성 화합물은 safrole (LC50, 8.22–16.10 ppm), terpinolene (11.85–15.32 ppm), g-terpinene (12.64–17.11 ppm), (–)-β-pinene (12.87–18.03 ppm), (+)-limonene (13.26–24.47 ppm), 3-carene (13.83–19.19 ppm), 그리고 α-phellandrene (13.84–23.08 ppm)이었으며, 비교 대상인 fenthion (LC50, 0.023–0.029), temephos (0.016–0.020)보다는 낮은 독성을 보였다. 이 결과는 세신 근경 정유 및 그 구성 화합물이 잠재적인 모기 유충방제제로 이용될 수 있는 가능성을 시사한다. 세신 근경에서 동정한 (–)-asarinin, α-asarone, methyleugenol, pellitorine, 그리고 pentadecane의 독성평가를 살충제-감수성 빨간집모기[Culex pipiens pallens (KS-CP strain)], 에집트숲모기(Aedes aegypti), 토고숲모기(Ochlerotatus togoi) 그리고 다양한 살충제에 저항성을 가지는 야외 빨간집모기[Culexx pipiens pallens (DJ-CP colony)]의 모기 3령기 유충을 이용하여 실시하였으며, 중합효소 연쇄반응을 확인하였다. 결과는 사용되고 있는 모기 유충 살충제 fenthion 그리고 temephos와 비교하였다. 살충제-감수성 빨간집모기[Culex pipiens pallens (KS-CP strain)], 에집트숲모기(Aedes aegypti), 토고숲모기(Ochlerotatus togoi) 모기 3종의 3령기 유충에 대하여 Pellitorine (LC50, 2.08, 2.33, 2.38 ppm)은 (–)-asarinin, α-asarone, 그리고 methyleugenol보다 각각 5.5–25.6배 4.5–24.7배, 그리고 6.9–24.6배 높은 독성을 보였으며, pentadecane은 가장 낮은 독성을 보였다. 전체적으로 모든 화합물은 fenthion과 temephos보다는 낮은 독성을 보였다. 세신 근경 유래물질 중 특히 (–)-asarinin과 pellitorine은 살충제 저항성 모기 개체수 조절과 수생 환경에 노출된 높은 독성의 합성 살충제의 수준을 줄이기 위한 세계적인 노력에 부합하는 추가적인 연구가 필요함을 시사한다. Pellitorine을 독립적으로 사용하였을 때와 pellitorine을 (–)-asarinin, α-asarone, methyleugenol, pentadecane와 1:1, 1:2, 1:3, 2:1, 그리고 3:1 비율로 혼합한 이진 화합물로 처리하였을 때 살충제-감수성 빨간집모기(KS-CP strain), 살충제-저항성 빨간집모기(DJ-CP colony) 각각의 3령기 유충에 대한 독성평가를 직접-접촉 생물검정을 통해 실시하였다. Pellitorine과 asarinin (3:1비율) 이진 혼합물은 KS-CP 유충과 DJ-CP 유충에서 각각 0.95ppm, 1.07ppm으로 상당히 높은 독성을 보였으며, pellitorine [KS-CP (2.08 ppm), DJ-CP(2.33 ppm)]과 asarinin(11.45, 12.61 ppm)을 단독적으로 사용하였을 때보다 독성이 높음을 확인하였다. 기타 비율의 혼합물과 pellitorine은 모두 비슷한 독성을 나타내었다. 공동 독성계수(co-toxicity, CC)와 상승 인자(synergistic factor, SF)를 바탕으로 확인하였을 때 3개 비율의 이진 혼합물(1/3, 2/1, 3/1)에서 상승패턴[KS-CP (CC, 250–390/ SF, 1.4–2.2)DJ-CP (CC, 257–279 그리고 SF, 1.1–2.1)]을 확인할 수 있었다. Pellitorine과 (–)-asarinin 이진 혼합물은 살충제 저항성 모기 유충 개체수 조절에 사용할 수 있는 가능성을 보여준다. 인도 식물인 Millettia pinnata 종자에서 유래한 활성 물질의 독성 평가를 살충제-감수성 빨간집모기, 에집트숲모기 그리고 야생 흰줄숲모기에 대하여 직접-접촉법 생물검정법을 이용하여 평가하였다. 결과는 모기 방제에 사용되는 fenthion, temephos와 비교하였다. Millettia pinnata의 활성물질을 분광분석법을 이용하여 탐색한 결과 karanjin (1), karanjachromene (2), pongamol (3), pongarotene (4), 올레산 (5), and 팔미트산 (6)으로 확인하였다. 24시간 노출한 반수치사농도(LC50)를 바탕으로 생물검정 결과 karanjin (14.61 and 16.13 mg/L)이 가장 높은 독성을 보였으며, 다음으로 올레산 (18.07 and 18.45 mg/L) 그리고 karanjachromene (18.74 and 20.57 mg/L) 순으로 높은 활성을 보였다. 에집트숲모기와 빨간집모기에서 이 구성 성분은 fenthion (LC50, 0.0031과 0.0048 mg/L) 또는 temephos (0.021과 0.050 mg/L)보다는 낮은 독성을 보였다. pongamol (LC50, 23.95와 25.76 mg/L), pongarotene (25.52와 37.61 mg/L), 그리고 팔미트산 (34.50 and 42.96 mg/L)은 낮은 독성을 나타내었다. 올레산 (LC50, 18.79 mg/L)은 흰줄숲모기에서 가장 높은 독성을 나타내었으며, 나머지 성분(LC50, 35.26- 85.61 mg/L)은 낮은 활성을 나타내었다. M. pinnata 종자 유래 활성 물질, 특히 karanjin, karanjachromene, 그리고 올레산의 경우 살충제 저항성 모기 개체 수 조절과 수생 환경에 노출된 높은 독성의 합성 살충제의 수준을 줄이기 위한 세계적인 노력에 부합하는 추가적인 연구가 필요함을 시사한다. 식물유래 물질의 살충메커니즘의 연구는 모기방제를 위해 실제적으로 중요하다. 첫째로 살충메커니즘에 대한 지식은 인간 또는 비대상 생물에 대한 독성을 이해하는데 중요하다. 두번째로 유사한 메커니즘에 작용하는 화합물의 개발에 있어 기반지식으로 활용될 수 있다. 마지막으로 해충 저항성 발현의 원인에 대한 중요한 단서를 제공하는 동시에 해충의 저항성을 줄이거나, 발현을 억제하는 대책에 도움을 줄 수 있다. 따라서 선발된 화합물에 대한 살충메커니즘을 밝히기 위해 아세틸콜린에스터라제 (AChE)의 저해를 조사하고, 조직병리학적으로 화합물 처리시 모기유충 위장의 변화를 관찰하였다. 에집트숲모기 3령기 유충을 이용한 AChE 저해 실험에서 반수저해농도(IC50)를 확인하였을 때 분리•확인된 화합물(IC50>×10-7)은 AChe 저해를 확인할 수 있었으나, 상용화된 살충제 dichlorvos (DDVP) (IC50>4×10-7)보다 강한 저해는 확인할 수 없었다. 조직병리학적인 연구에서는 pellitorine을 처리하였을 때 유충 내의 세포소기관이 관통, 치환 그리고 파괴되는 것을 확인할 수 있었다. 투과전자현미경(Transmission electron microscope, TEM) 사진을 통해 처리 24시간 후 세포소기관의 손상을 확실히 확인할 수 있었다.Mosquitoes are prevalent worldwide and common and serious disease vectoring insect pest. Mosquito larval abatement has been achieved principally by the use of organophosphorus insecticides (OPs), insect growth regulators, and bacterial larvicides. Continued and repeated use of these larvicides has disrupted natural biological control systems and led to resurgences of mosquitoes, often resulted in the widespread development of resistance, and has undesirable effects on aquatic nontarget organisms, and fostered environmental and human health concerns. Therefore, right now use of eco-friendly and cost-free plant based products for the control of mosquitoes is inevitable. Currently, numerous products of botanical origin, especially the secondary metabolites, have received considerable renewed attention as potentially bioactive agents used in insect vector management. In addition, studies on the mode of action of insecticides or plant-derived constituents are very important because it helps chemists to design additional chemicals with similar mode of action and because it could give scientists important clues as to the cause of resistance development in pests, particularly that involving target insensitivity, and thereby helps in designing countermeasures to avoid resistance or reverse the development of resistance. In this study, an assessment was made of the toxicity of constituents identified in Asarum heterotropoides root steam distillate, methanolic extract of the plant root, and Indian native plant Millettia pinnata (formerly known as Pongamia pinnata) seeds against third instars from insecticide-susceptible and -resistant mosquito species. The possible mode of action and delivery of the constituents are also examined. The toxicity of A. heterotropoides root steam distillate constituents to third instars of Culex pipiens pallens, Aedes aegypti, and Ochlerotatus togoi (formerly Aedes togoi) was examined using a direct-contact mortality bioassay. Results were compared with those following the treatment with OPs fenthion and temephos. A. heterotropoides root steam distillate exhibited good larvicidal activity (21.07–27.64 mg/L) against three mosquito species, based on LC50 values. Potent activity was produced by safrole (LC50, 8.22–16.10 mg/L), terpinolene (11.85–15.32 mg/L), g-terpinene (12.64–17.11 mg/L), (–)-β-pinene (12.87–18.03 mg/L), (+)-limonene (13.26–24.47 mg/L), 3-carene (13.83–19.19 mg/L), and α-phellandrene (13.84–23.08 mg/L), although the larvicidal activity of these compounds was less toxic than either fenthion (LC50, 0.023–0.029 mg/L) or temephos (0.016–0.020 mg/L). The toxicity of (–)-asarinin, α-asarone, methyleugenol, pellitorine, and pentadecane identified in A. heterotropoides root to third instars from insecticide-susceptible Cx. p. pallens (KS-CP strain), Ae. aegypti, and Ochlerotatus togoi, as well as field-collected Cx. p. pallens (DJ-CP colony), identified by polymerase chain reaction, were compared with those of two mosquito larvicides: fenthion and temephos. Pellitorine (LC50, 2.08, 2.33, and 2.38 mg/L) was 5.5, 10.8, and 25.6 times, 4.5, 11.6, and 24.7 times, and 6.9, 11.1, and 24.6 times more toxic than (–)-asarinin, α-asarone, and methyleugenol against susceptible Cx. p. pallens, Ae. aegypti, and Oc. togoi larvae, respectively. Pentadecane was least toxic. Overall, all the compounds were less toxic than either fenthion or temephos. The toxic effect of pellitorine alone or in combination with (–)-asarinin, α-asarone, methyleugenol, and pentadecane (1:1, 1:2, 1:3, 2:1, and 3:1 ratios) to third instars from insecticide-susceptible KS-CP strain and -resistant DJ-CP colony of Cx. p. pallens was likewise evaluated. Binary mixture of pellitorine and asarinin (3:1 ratio) was significantly more toxic against KS-CP larvae (0.95 mg/L) and DJ-CP larvae (1.07 mg/L) than either pellitorine (2.08 mg/L for KS-CP and 2.33 mg/L for DJ-CP) or asarinin (11.45 and 12.61 mg/L) alone. The toxicity of the other binary mixtures (1:1, 1:2, 1:3, and 2:1 ratios) and pellitorine did not differ significantly from each other. Based on the co-toxicity coefficient (CC) and synergistic factor (SF), the three binary mixtures (1:3, 2:1, and 3:1) operated in a synergy pattern (CC, 250–390 and SF, 1.4–2.2 for KS-CPCC, 257–279 and SF, 1.1–2.1 for DJ-CP). The toxicity of constituents derived from the seeds of Millettia pinnata to third instars of insecticide-susceptible Cx. p. pallens and Ae. aegypti and wild Aedes albopictus was examined. Results were compared with those of fenthion and temephos. The active principles of M. pinnata were identified as the karanjin (1), karanjachromene (2), pongamol (3), pongarotene (4), oleic acid (5), and palmitic acid (6) by spectroscopic analysis. Based on 24 h LC50 values, karanjin (14.61 and 16.13 mg/L) was the most toxic compound, followed by oleic acid (18.07 and 18.45 mg/L) and karanjachromene (18.74 and 20.57 mg/L). These constituents were less toxic than either fenthion (LC50, 0.0031 and 0.0048 mg/L) or temephos (0.021 and 0.050 mg/L) against Ae. aegypti and Cx. p. pallens. Low toxicity was produced by pongamol (LC50, 23.95 and 25.76 mg/L), pongarotene (25.52 and 37.61 mg/L), and palmitic acid (34.50 and 42.96 mg/L). Against third instars from Ae. alpopictus, oleic acid (LC50, 18.79 mg/L) was most toxic. Low toxicity was observed with the other five constituents (LC50, 35.26–85.61 mg/L). Enzyme kinetics analysis acetylcholinesterase (AChE) was analyzed to identify compounds and also observed gastrointestinal changes of treated compounds through histopathological section. In AChE inhibition assay, there is no potent inhibition was observed (IC50 >10–7) in isolated and identified compounds when compare with commercially available larvicides dichlorvos (DDVP) (IC50 >4 × 10–7) against third instars of Ae. aegypti. The histopathological effects of pellitorine on larval segments of third instars of Aedes aegypti were examined by transmission electron microscopy. Results were compared with those of deltamethrin. At a concentration of 5 mg/L, pellitorine was targeted mainly on midgut epithelium and anal gills, indicating variably dramatic degenerative response of the midgut through a sequential epithelial disorganization. The anterior midgut was almost entirely necrosed, bearing only residues inside the plasma membranes on the basal lamina. The compound has shown complete damage of all glandular cells of anal gills, because cuticle damage was occurred by pellitorine. The histopathological effects 2.5 mg/L of deltamethrin on the different regions of the midgut clearly indicate the epithelial disorganization and delocalization of cell organelles which have been correlated with their morphofunctional status. Based on these results, pellitorine merit further study as a potential larvicide with a specific target site and mode of delivery or a lead molecule for the control mosquito populations. In conclusion, A. heterotropoides root-derived materials, particularly (–)-asarinin and pellitorine, and M. pinnata seed-derived materials, particularly karanjin, karanjachromene, and oleic acid, merit further study as potential mosquito larvicides for the control of insecticide-resistant mosquito populations in the light of global efforts to reduce the level of highly toxic synthetic insecticides in the aquatic environment.TABLE OF CONTENTS ABSTRACT LIST OF ABBREVIATIONS LIST OF TABLES LIST OF FIGURES INTRODUCTION LITERATURE REVIEW CHAPTER I Isolation and Identification of Larvicidal Constituents Identified in Asarum heterotropoides Root 1.1. Larvicidal Activity of Asarum heterotropoides Root Steam Distillate Constituents against Culex pipiens pallens, Aedes aegypti, and Ochlerotatus togoi (Diptera: Culicidae) INTRODUCTION MATERIALS AND METHODS 1.1.1. Chemicals 1.1.2. Mosquitoes 1.1.3. Steam Distillation 1.1.4. Gas Chromatography 1.1.5. Gas Chromatography-Mass Spectroscopy 1.1.6. Bioassay 1.1.7. Data Analysis RESULTS 1.1.1. Chemical Constituents of A. heterotropoides Root Steam Distillate 1.1.2. Larvicidal Activity of Test Compounds DISCUSSION 1. 2. Larvicidal Activity of Asarum heterotropoides Root Constituents against Insecticide-Susceptible and -Resistant Culex pipiens pallens and Aedes aegypti and Ochlerotatus togoi INTRODUCTION MATERIALS AND METHODS 1.2.1. General Instrumental Methods 1.2.2. Chemicals 1.2.3. Mosquitoes 1.2.4. Extraction and Isolation 1.2.5. Bioassay 1.2.6. Data Analysis RESULTS 1.2.1. Bioassay-Guided Fractionation and Isolation 1.2.2. Larvicidal Activity of Insecticides 1.2.3. Larvicidal Activity of Test Compounds 1.2.4. Species Susceptibility DISCUSSION 1.3. Enhanced Toxicity of Binary Mixtures of Larvicidal Constituents from Asarum heterotropoides Root to Insecticide-Susceptible and -Resistant Culex pipiens pallens INTRODUCTION MATERIALS AND METHODS 1.3.1. Chemicals 1.3.2. Mosquitoes 1.3.3. Bioassay 1.3.4. Data Analysis RESULTS DISCUSSION CHAPTER II Isolation and Identification of Larvicidal Principles Identified in Millettia pinnata Seed against Insecticide-Susceptible Culex pipiens pallens and Aedes aegypti and Wild Aedes albopictus INTRODUCTION MATERIALS AND METHODS 2.1. General Instrumental Methods 2.2. Chemicals 2.3. Mosquitoes 2.4. Plant Material 2.5. Extraction and Isolation 2.6. Steam Distillation 2.7. Gas Chromatography 2.8. Gas Chromatography-Mass Spectroscopy 2.9. Bioassay 2.10. Data Analysis RESULTS 2.1. Chemical Constituents of Indian Beech Seed Steam Distillate 2.2. Bioassay-Guided Fractionation and Isolation 2.3. Larvicidal Activity of Test Compounds 2.3. Larvicidal Activity of Steam Distillate Constituents DISCUSSION CHAPTER III Acetylcholinesterase Inhibition and Histopathological effects of phytochemicals on the midgut epithelium: Possible mode of action against mosquito larvae 3.1. Actylcolineesterase (AChE) inhibition of phytochemicals INTRODUCTION MATERIALS AND METHODS 3.1.1. Chemicals and Reagents 3.1.2. Acetylcholinesterase (AChE) Assay RESULTS DISCUSSION 3. 2. Histopathological effects of pellitorine INTRODUCTION MATERIALS AND METHODS 3.2.2. Chemicals and Reagents 3.2.2. Transmission Electron Microscopy RESULTS AND DISCUSSION CONCLUSION LITERATURE CITEDDocto

Growth, photoluminescence, lifetime, and laser damage threshold studies of 1, 3, 5-triphenylbenzene (TPB) single crystal for scintillation application

The 1, 3, 5-triphenylbenzene (TPB) single crystal has been grown using slow cooling seed rotation technique. Optical transmittance of the grown crystal was obtained from UV-Visible analysis. The grown TPB crystal has good transmission in the entire visible region with a lower cutoff wavelength of 330 nm. The solubility of TPB material was determined using toluene as a solvent with different temperatures. The full width at half maximum is 18 arcsec, which indicates that the crystal is of good quality. The TPB crystal was excited (lambda (exc)) at 307 nm, and the corresponding emission (lambda (em)) has been observed at 352 nm. The laser-induced damage threshold (LDT) value of grown crystal is 1.25 GW/cm(2). Third-order nonlinear optical susceptibility chi (3) is determined using the Z-scan technique as 3.07422x10(-09) esu. The TPB crystal proves its suitability for scintillation applications and optoelectronic device fabrications

Determination of Residual Epichlorohydrin in Sevelamer Hydrochloride by Static Headspace Gas Chromatography with Flame Ionization Detection

A sensitive static headspace gas chromatographic method was developed and validated for the determination of residual epichlorohydrin (ECH) in sevelamer hydrochloride (SVH) drug substance. This method utilized a Phenomenex Zebron ZB-WAX GC column, helium as carrier gas with flame ionization detection. The critical experimental parameters, such as, headspace vial incubation time and incubation temperature were studied and optimized. The method was validated as per United States Pharmacopoeia (USP) and International Conference on Harmonization (ICH) guidelines in terms of detection limit (DL), quantitation limit (QL), linearity, precision, accuracy, specificity and robustness. A linear range from 0.30 to 10 μg/mL was obtained with the coefficient of determination (r2) 0.999. The DL and QL of ECH were 0.09 μg/mL and 0.30 μg/mL, respectively. The recovery obtained for ECH was between 91.7 and 96.6%. Also, the specificity of the method was proved through gas chromatography mass spectrometry (GC-MS). This method was applied successfully to determine the content of residual ECH in SVH bulk drug

A novel olfactory pathway is essential for fast and efficient blood-feeding in mosquitoes

In mosquitoes, precise and efficient finding of a host animal is crucial for survival. One of the poorly understood aspects of mosquito blood-feeding behavior is how these insects target an optimal site in order to penetrate the skin and blood vessels without alerting the host animal. Here we provide new findings that a piercing structure of the mouthpart of the mosquitoes, the stylet, is an essential apparatus for the stage in blood feeding. Indeed, the stylet possesses a number of sensory hairs located at the tip of the stylet. These hairs house olfactory receptor neurons that express two conventional olfactory receptors of Aedes aegypti (AaOrs), AaOr8 and AaOr49, together with the odorant co-receptor (AaOrco). In vivo calcium imaging using transfected cell lines demonstrated that AaOr8 and AaOr49 were activated by volatile compounds present in blood. Inhibition of gene expression of these AaOrs delayed blood feeding behaviors of the mosquito. Taken together, we identified olfactory receptor neurons in the stylet involved in mosquito blood feeding behaviors, which in turn indicates that olfactory perception in the stylet is necessary and sufficient for mosquitoes to find host blood in order to rapidly acquire blood meals from a host animal

Advancing sustainable agriculture: a critical review of smart and eco-friendly nanomaterial applications

Undoubtedly, nanoparticles are one of the ideal choices for achieving challenges related to bio sensing, drug delivery, and biotechnological tools. After gaining success in biomedical research, scientists are exploring various types of nanoparticles for achieving sustainable agriculture. The active nanoparticles can be used as a direct source of micronutrients or as a delivery platform for delivering the bioactive agrochemicals to improve crop growth, crop yield, and crop quality. Till date, several reports have been published showing applications of nanotechnology in agriculture. For instance, several methods have been employed for application of nanoparticles; especially metal nanoparticles to improve agriculture. The physicochemical properties of nanoparticles such as core metal used to synthesize the nanoparticles, their size, shape, surface chemistry, and surface coatings affect crops, soil health, and crop-associated ecosystem. Therefore, selecting nanoparticles with appropriate physicochemical properties and applying them to agriculture via suitable method stands as smart option to achieve sustainable agriculture and improved plant performance. In presented review, we have compared various methods of nanoparticle application in plants and critically interpreted the significant differences to find out relatively safe and specific method for sustainable agricultural practice. Further, we have critically analyzed and discussed the different physicochemical properties of nanoparticles that have direct influence on plants in terms of nano safety and nanotoxicity. From literature review, we would like to point out that the implementation of smaller sized metal nanoparticles in low concentration via seed priming and foliar spray methods could be safer method for minimizing nanotoxicity, and for exhibiting better plant performance during stress and non-stressed conditions. Moreover, using nanomaterials for delivery of bioactive agrochemicals could pose as a smart alternative for conventional chemical fertilizers for achieving the safer and cleaner technology in sustainable agriculture. While reviewing all the available literature, we came across some serious drawbacks such as the lack of proper regulatory bodies to control the usage of nanomaterials and poor knowledge of the long-term impact on the ecosystem which need to be addressed in near future for comprehensive knowledge of applicability of green nanotechnology in agriculture