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2018

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Articles 12511 - 12524 of 12524

Full-Text Articles in Life Sciences

Optimization Of Protein Hydrolysate Preparation And Their Angiotensin I-Converting Enzyme Inhibitory Activity From Shiitake Mushrooms Lentinula Sp., Supawee Paisansak Jan 2018

Optimization Of Protein Hydrolysate Preparation And Their Angiotensin I-Converting Enzyme Inhibitory Activity From Shiitake Mushrooms Lentinula Sp., Supawee Paisansak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Angiotensin-I converting enzyme (ACE) is a key enzyme involved in regulating blood pressure. ACE converts angiotensin-I into angiotensin-II, which results in raised blood pressure. Inhibition of ACE leads to a decreased concentration of angiotensin-II and lowering of blood pressure. Food protein-derived ACE inhibitory peptides are considered to be a safer alternative to antihypertensive drugs. Shiitake mushrooms, one of the most consumed mushrooms in Thailand, are recognized as a nutritive food with health-stimulating properties. The aim of this study was to optimize the preparation of a shiitake-protein hydrolysate and investigate the ACE inhibitory activity of the hydrosylate. Shiitake mushrooms were hydrolyzed …


Glycation And Α-Glucosidase Inhibitors From Boesenbergia Rotunda And Lansium Parasiticum, Thammatee Potipiranun Jan 2018

Glycation And Α-Glucosidase Inhibitors From Boesenbergia Rotunda And Lansium Parasiticum, Thammatee Potipiranun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Glycation is spontaneous non-enzymatic reaction between protein and glycation precursors; methylglyoxal (MG) that initially yields advanced glycation end-products (AGEs), which ultimately trigger to several severe complications. Therefore, the inhibition of AGEs formation is the imperative approach for alleviating diabetic complications. Moreover, one of typical diabetic therapy is α-glucosidase inhibition to reduce glucose level in bloodstream. Therefore, this research aims to study bioactivity and mechanism of natural products to inhibit glycation and α-glucosidase. From preliminary study of some phenolic compounds, flavanones from fingerroot (Boesenbergia rotunda) could inhibit glycation. The dichloromethane extract of fingerroot afforded three flavanones (pinocembrin, pinostrobin, and alpinetin), two …


Flowering Phenology And Pollination Biology Of Ceropegia Thailandica Meve And Ceropegia Suddeei Kidyoo, Chayanin Kraithep Jan 2018

Flowering Phenology And Pollination Biology Of Ceropegia Thailandica Meve And Ceropegia Suddeei Kidyoo, Chayanin Kraithep

Chulalongkorn University Theses and Dissertations (Chula ETD)

The flowers of the genus Ceropegia have complex structures that involve in pollination mechanism. These structres gynostegium, pollinarium and corona. Moreover, the corolla tube which is inflated at base and the corolla lobes are connate only at tip forming a cage-like structure functions as a trap. When pollinators are attracted to flower, they could be temporarily trapped inside the flower. From previous studies, there are about 18 species in Thailand. Most Thai species have flowers characterized by a long narrow corolla lobe with distinct inflated basal portion. However, some species have a short corolla tube, such as C. thailandica Meve. …


Taxonomic Revision And Pollination Biology Of Orchid Genera Crepidium Blume And Dienia Lindl. (Malaxidinae, Orchidaceae) In Thailand, Anchalee Nuammee Jan 2018

Taxonomic Revision And Pollination Biology Of Orchid Genera Crepidium Blume And Dienia Lindl. (Malaxidinae, Orchidaceae) In Thailand, Anchalee Nuammee

Chulalongkorn University Theses and Dissertations (Chula ETD)

The terrestrial orchid Crepidium Blume and Dienia Lindl. in Thailand were enumerated by Gunnar Seidenfaden under Malaxis with key and drawings. Because of no species descriptions in publication, it is difficult to delimit species boundary. Moreover, recent discovery of new species results in unreliable assessment of species, therefore, the taxonomic revision of Crepidium and Dienia in Thailand should be carried out. The results indicated that the column and transversal callus on labellum are taxonomically important characters to delimit these two genera. In addition, morphological characters, i.e. stem and leaf morphology, labellum auricles, margins and number of teeth on distal margin …


Taxonomic Revision Of The Fern Family Athyriaceae In Thailand, Puttamon Pongkai Jan 2018

Taxonomic Revision Of The Fern Family Athyriaceae In Thailand, Puttamon Pongkai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The most up-to-date account of the Athyriaceae is in Flora of Thailand. This account includes seven genera, i.e. Athyrium, Anisocampium, Cornopteris, Deparia, Diplazium, Hypodematium and Kuniwatsukia. Previously, the taxonomic relationships among genera were ambiguous and not well understood. The existing keys and descriptions are uncertain and do not include some unknown taxa. This research aims to clarify the taxonomic status of this family and its genera based on morphological, anatomical, palynological and molecular data. The results indicated that the types and shapes of frond, scale types, sorus shapes, shapes of vascular bundle and ornamentation of spores are valuable characters for …


การสะสมของพิษอัมพาตในหอยแมลงภู่ Perna Viridis จากการกรองกิน Alexandrium Minutum ที่แยกจากบริเวณปากแม่น้ำเจ้าพระยา, ปฏิภาณ พุ่มพวง Jan 2018

การสะสมของพิษอัมพาตในหอยแมลงภู่ Perna Viridis จากการกรองกิน Alexandrium Minutum ที่แยกจากบริเวณปากแม่น้ำเจ้าพระยา, ปฏิภาณ พุ่มพวง

Chulalongkorn University Theses and Dissertations (Chula ETD)

Alexandrium minutum เป็นไดโนแฟลกเจลเลตที่เป็นสาเหตุของพิษอัมพาตในหอย สามารถพบการกระจายในปริมาณน้อยเป็นบางครั้งบริเวณชายฝั่งอ่าวไทย เนื่องจากบริเวณอ่าวไทยเป็นพื้นที่เลี้ยงหอยแมลงภู่ที่สำคัญของประเทศ ทำให้มีความเป็นไปได้ของการสะสมพิษอัมพาตในหอยแมลงภู่จากการกรองกิน A. minutum อย่างไรก็ตามการศึกษาการสะสมพิษอัมพาตในหอยแมลงภู่ในประเทศไทยยังมีอยู่อย่างจำกัด เพื่อให้เกิดความเข้าใจมากขึ้น จึงทำการศึกษาการสะสมพิษอัมพาตในหอยแมลงภู่ (Perna viridis) และแพลงก์ตอนพืชที่กรองแยกจากน้ำทะเลในพื้นที่เลี้ยงหอย บริเวณศรีราชา จังหวัดชลบุรี และคลองด่าน จังหวัดสมุทรปราการ ในฤดูลมมรสุมตะวันตกเฉียงใต้ และฤดูลมมรสุมตะวันออกเฉียงเหนือ และการสะสมพิษอัมพาตที่ส่งผ่านจาก A. minutum ไปสู่หอยแมลงภู่ในห้องปฏิบัติการ ด้วยการให้หอยกรองกิน A. minutum อย่างต่อเนื่องเป็นเวลา 2 สัปดาห์ และในช่วงเวลากำจัดพิษ ให้หอยกรองกินแพลงก์ตอนชนิด Isochrysis sp. ซึ่งไม่สร้างสารชีวพิษเป็นเวลา 2 สัปดาห์ ทำการตรวจวัดปริมาณและองค์ประกอบพิษอัมพาตโดยเครื่อง HPLC ด้วยวิธีตรวจวัดแบบ pre-chromatographic oxidation ผลการศึกษาในพื้นที่เลี้ยงหอยแมลงภู่ ไม่พบเซลล์ของ A. minutum แต่พบปริมาณพิษอัมพาตในหอยแมลงภู่อยู่ในระดับต่ำกว่าเกณฑ์มาตรฐานสารชีวพิษกลุ่มพิษอัมพาตในหอยสองฝา การศึกษาในห้องปฏิบัติการ ใช้เซลล์ A. minutum ที่เติบโตในช่วงปลายของระยะ exponential ซึ่งมีปริมาณพิษอัมพาตอยู่ในช่วง 3.75-4.46 pgSTXeq./เซลล์ และมี GTX1,4 เป็นองค์ประกอบพิษหลักมากกว่า 90% เป็นอาหารแก่หอยแมลงภู่ ผลการทดลองพบว่าปริมาณพิษอัมพาตที่สะสมในหอยแมลงภู่ต่อตัวเพิ่มขึ้นสอดคล้องกับปริมาณ A. minutum ที่ถูกกรองกิน ปริมาณพิษอัมพาตมีค่ามากกว่าค่าควบคุมภายใน 24 ชั่วโมง และมีค่าสูงสุดในวันสุดท้ายที่กรองกิน A. minutum คือ วันที่ 14 (11.20 µg STXeq.ต่อตัว) ซึ่งมีค่าสูงกว่าระดับควบคุม 14 เท่า โดยตลอดช่วงการศึกษาพบการสะสมพิษอัมพาตมีค่าอยู่ระหว่าง 23-47% ของปริมาณที่ได้รับจากการกรองกิน ในช่วงการกำจัดพิษพบว่า ปริมาณพิษอัมพาตต่อตัวหอยลดลงอย่างรวดเร็วและต่ำกว่าค่าควบคุมภายใน 3 วัน โดยในวันสุดท้ายของการกำจัดพิษพบพิษอัมพาต 0.08% จากปริมาณที่ได้รับ นอกจากนี้ยังพบความแตกต่างของการกำจัดพิษอัมพาตที่ได้รับจาก A. minutum คือ GTX1,4 (อนุพันธ์ที่มีความเป็นพิษสูง) สามารถถูกกำจัดจากเนื้อหอยอย่างรวดเร็ว และการที่องค์ประกอบของพิษอัมพาตแต่ละชนิดมีการเปลี่ยนแปลงตลอดช่วงการทดลอง แสดงให้เห็นความสามารถของกระบวนการทางชีวเคมีของหอยในการกำจัดพิษอัมพาตออกจากร่างกาย การศึกษาครั้งนี้แสดงให้เห็นได้ว่าพิษอัมพาตจาก …


Production And Characterization Of Cutinase From Tropical Fungi And Application With Detergent For Stain And Fuzz Removal From Spun Polyester Fabrics, Taweeporn Sooksai Jan 2018

Production And Characterization Of Cutinase From Tropical Fungi And Application With Detergent For Stain And Fuzz Removal From Spun Polyester Fabrics, Taweeporn Sooksai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fungi were isolated from agricultural soil and plant specimens. Twenty three isolates from 44 fungal isolates were found to produce cutinase by using PCL-plate clearing assay and their cutinase activity were investigated. All the cutinase-producing fungi were cultured in liquid mineral medium (LMM) containing PCL or crude cutin extracted from papaya peels, which was a carbon source for cutinase production. Cutinase activity was assayed base on the hydrolysis of paranitrophenyl butarate (p-NPB). It was found that PBURU-T5 gave the highest cutinase activity. The isolate PBURU-T5 was selected for identification based on morphology together with comparative nucleotide sequencing from internal transcribed …


Application Of Konjac Glucomannan To Encapsulate And Stabilize The Curcumin In Milk System, Afwa Hayuningtyas Jan 2018

Application Of Konjac Glucomannan To Encapsulate And Stabilize The Curcumin In Milk System, Afwa Hayuningtyas

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigated the influence of different concentration of konjac glucomannan (KGM) (0, 0.1, 0.2, 0.3 % (w/v)) on the stability of curcumin emulsion in milk system containing 10%, 20%, and 30% (v/v) oil volume fraction. The data of creaming index, curcumin concentration, apparent viscosity, and color were obtained to investigate the stability of the system. Emulsions that reached the physical stability until 14 days of storage at 4ᵒC were subjected to further analysis including antioxidant, particle size, zeta potential, and bioaccessibility by the simulated gastrointestinal tract (GIT). The result suggested that increasing KGM concentration significantly increased the viscosity of …


Effect Of Temperature On Antioxidant Enzyme Activities And Gene Expression In Sand Worm Perinereis Quatrefagesi (Grube, 1878), Sucharat Suksai Jan 2018

Effect Of Temperature On Antioxidant Enzyme Activities And Gene Expression In Sand Worm Perinereis Quatrefagesi (Grube, 1878), Sucharat Suksai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Polychaetes is one of intertidal animals that face the fluctuations of coastal environment through time. One of important environmental factors to animals is temperature regarding to the fluctuation of temperature in intertidal environment. Human activities could also cause high changes in water temperature by high temperature discharges from urban and industries. Since global warming is still a main issue, an increase of seawater temperature about 3°C could be possible as a prediction. This study aimed to investigate effect of temperature in polychaetes Perinereis quatrefagesi at cellular level, which could be indicated by heat shock response and oxidative stress due to …


Characterizing Immune Response To Hiv-1 Infection In Bicd2-Knockout Cells, Omar Abdel-Rahim Jan 2018

Characterizing Immune Response To Hiv-1 Infection In Bicd2-Knockout Cells, Omar Abdel-Rahim

Master's Theses

An important part of the HIV-1 infection cycle is the attachment of the intracellular viral core to the host microtubule network, facilitated by attachment of the viral capsid to cargo adaptor proteins. One such cargo adaptor is Bicaudal D Homolog Protein 2 (BICD2). BICD2 can attach to both the HIV-1 capsid and the dynein/dynactin complex and facilitate the trafficking of the viral core towards the host nucleus. Removal of BICD2 can disrupt this viral translocation, resulting in an elevated immune response that impairs productive HIV-1 infection. In my research, we investigated what viral particles are detected in the absence of …


Induction Of Zika Virus-Specific Cd8+ T Cells By Means Of Dna Vaccine, Frank Gambino Jr. Jan 2018

Induction Of Zika Virus-Specific Cd8+ T Cells By Means Of Dna Vaccine, Frank Gambino Jr.

Master's Theses

Zika virus (ZIKV) is a member of the virus family flaviviridae and is transmitted via Aedes aegypti mosquitos. Monoclonal antibodies against dengue virus have been found to cross-react with ZIKV but show no ability to neutralize it. Further studies have shown that Stat2-/- mice given plasma from dengue positive donors exhibit a heightened disease phenotype when challenged with ZIKV. Antibody dependent enhancement is theorized to cause such effect. The goal of this study was to design a plasmid which, when encoded, creates an antigen that will be used to stimulate exclusively CD8+ T cells. The gene sequence of NS3 was …


Cryptic Diversification Of Two Widespread Species In Madagascar, Lynika Sharlice Strozier Jan 2018

Cryptic Diversification Of Two Widespread Species In Madagascar, Lynika Sharlice Strozier

Master's Theses

Using phylogenetic and phylogeographic tools to uncover hidden diversity within the genus Newtonia in Madagascar

Madagascar is known for its rich biodiversity and high level of endemic species that are found nowhere else. Cryptic diversification, defined as genetically and evolutionarily distinct species that are hard to detect because they are morphologically indistinguishable from their closest relatives, has been hypothesized to occur in many groups on Madagascar. Currently it is unclear to what extent this phenomenon occurs in birds because only a few studies have been conducted. My study examined the phylogenetic and phylogeographic patterns within a songbird genus, Newtonia, that …


Lidocaine Attenuates An Induced Inflammatory Response, Stephanie Zack Jan 2018

Lidocaine Attenuates An Induced Inflammatory Response, Stephanie Zack

Master's Theses

Inflammation is common to the pathogenesis of a variety of diseases. Therapeutics which can regulate and reduce damaging inflammation are therefore valuable in the treatment of inflammation and inflammatory diseases.

One commonly used analgesic, recently identified as limiting inflammation, is lidocaine. Additionally, alternative, less toxic therapeutics like the snake venom peptides, Zep 3 and Zep 4, are thought to have anti-inflammatory effects. Yet a well-defined mechanism or cellular target for lidocaine or Zep peptides' anti-inflammatory effects has not been proposed.

We aimed to determine whether lidocaine and Zep peptides reduce the release of the proinflammatory cytokine, IL-1β, from activated human …


Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack Jan 2018

Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack

Master's Theses

Chironomidae (Diptera) surface-floating pupal exuviae were collected monthly during the ice-free season in 2010-2011 from six lakes in the North Temperate Lakes Long-Term Ecological Research site in northern Wisconsin. The goal of this study was to determine whether chironomid community structure reflected differences in lake morphometry (i.e., depth, area, shoreline development, etc.), water chemistry, and/or landscape position (i.e., elevation). Forty-six genera were identified from four subfamilies: Chironominae (57%), Orthocladiinae (28%), Tanypodinae (11%), and Diamesinae (4%). Tanytarsus, Ablabesmyia, and Psectrocladius were found in all six study lakes; whereas certain genera, such as Omisus, Protanypus, and Epoicocladius were each observed in only …