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Microstructural Evolution And Mechanical Properties Of Zn-Ti Alloys For Biodegradable Stent Applications, Zhiyong Yin

Dissertations, Master's Theses and Master's Reports

Stents made of biodegradable metallic materials are increasingly gaining interest within the biomaterials field because of their superior mechanical properties and biodegradation rates as compared to polymeric materials. Zinc and its alloys have been developed and investigated as possible candidates for biodegradable stent applications in the last five years. This study intended to formulate and characterize a new series of Zn-Ti alloys, with titanium additions of less than 1-3 wt%, with the primary objective to develop and select an alloy that meets benchmark values of mechanical properties for biodegradable stents. A series of Zn-Ti alloys was formulated through vacuum induction …

Formulation And Testing Of Biodegradable Polymeric Coating On Zinc Wires In Cardiovascular Stent Application, Avishan Arab Shomali

Dissertations, Master's Theses and Master's Reports

Biodegradable and biocompatible poly (L-lactic-acid) (PLLA) coating was applied on a modified zinc (Zn) substrate by dip coating, with the intent to delay the bio-corrosion and slow the degradation rate of zinc substrate. 3-(Trimethoxysilyl) propyl methacrylate (MPS) was used for modification of the zinc substrate for promoting the adhesion between the metallic substrate and the polymer coating. It is hypothesized that the delay in Zn biodegradation could be useful in the first several weeks to prevent the early loss of mechanical integrity of the endovascular stent and to improve the healing process of the diseased vascular site. The PLLA coating …

An Integrative Description Of Mesobiotus Ethiopicus Sp. Nov. (Tardigrada: Eutardigrada: Parachela: Macrobiotidae: Harmsworthi Group) From The Northern Afrotropic Region, Daniel Stec, Reinhardt Møbjerg Kristensen

Turkish Journal of Zoology

A new species of the Mesobiotus harmsworthi group is described from Ethiopia. An integrative taxonomy approach was applied by combining morphological and morphometric analyses-imaging under phase contrast and scanning electron microscopy with molecular analysis (18S rRNA, 28S rRNA and COI markers)-to cross-verify the status of the population as a new species. The specimens of Mesobiotus ethiopicus sp. nov. are most similar to two taxa of the harmsworthi complex: M. harmsworthi obscurus (Dastych, 1985) and M. peterseni (Maucci, 1991). Nevertheless, the new species can be easily distinguished from the first of these taxa by the absence of additional teeth in the …

The Impact Of Sglt2 Inhibitors, Compared With Insulin, On Diabetic Bone Disease In A Mouse Model Of Type 1 Diabetes, Kathryn M. Thrailkill, Jeffry S. Nyman, R. Clay Bunn, Sasidhar Uppuganti, Katherine L. Thompson, Charles K. Lumpkin, Evangelia Kalaitzoglou, John L. Fowlkes

Barnstable Brown Diabetes Center Faculty Publications

Skeletal co-morbidities in type 1 diabetes include an increased risk for fracture and delayed fracture healing, which are intertwined with disease duration and the presence of other diabetic complications. As such, chronic hyperglycemia is undoubtedly a major contributor to these outcomes, despite standard insulin-replacement therapy. Therefore, using the streptozotocin (STZ)-induced model of hypoinsulinemic hyperglycemia in DBA/2J male mice, we compared the effects of two glucose lowering therapies on the fracture resistance of bone and markers of bone turnover. Twelve week-old diabetic (DM) mice were treated for 9 weeks with: 1) oral canagliflozin (CANA, dose range ~10-16 mg/kg/day), an inhibitor of …

The Effect Of Road Crossings On Stream-Associated Salamanders Within Holly Springs National Forest, Caleb Ashton Aldridge

Electronic Theses and Dissertations

Road crossings have significant effects on wildlife, but there is limited information on how road crossings affect stream-associated salamanders. Stream-associated salamanders are vital to their ecological communities and are likely to experience the effect of roads more readily than other species due to their physiological characteristics. To test the effects of road crossings on stream-associated salamanders, I surveyed 12 pairs of confluent streams – one stream crossed by a road and the other not in each pair – within Holly Springs National Forest, Mississippi. Surveys in the summer of 2015 were used to measure abundance and species richness of stream-associated …

Genome Editing And The Jurisprudence Of Scientific Empiricism, Paul Enriquez

Vanderbilt Journal of Entertainment & Technology Law

Humankind has reached, in tow by the hand of a scientific breakthrough called CRISPR, the Rubicon of precise genetic manipulation first envisioned over fifty years ago. Despite CRISPR's renown in science and its power to transform the world, it remains virtually unaddressed in legal scholarship. In the absence of on-point law, the scientific community has attempted to reach some consensus to preempt antagonistic regulation and prescribe subjective standards of use under the guise of a priori scientific empiricism. Significant and complex legal issues concerning this technology are emerging, and the void in legal scholarship is no longer tolerable.

This Article …

The Migrant Voice : The Politics Of Writing Home Between The Sinophone And Anglophone Worlds, Kenny K. K. Ng

Journal of Modern Literature in Chinese 現代中文文學學報

This paper addresses the politics of language, identity, and diasporic Chinese writing in old and emerging Chinese migrant literature. I opt for the idea of a “migrant subject” as brought up by Ha Jin to underscore a diverse verbal strategy and mobile literary creativity: that of the migrant writer who initiates linguistic and literary perversions to actively intervene in the cultural politics of both the host country and the motherland. The article proceeds to recuperate the diasporic narratives of Sinophone authors Bai Xianyong and Nie Hualing as two earlier examples of migrant writers before Ha, which exemplified the Cold War …

แนวคิดนิเวศสำนึกในวรรณกรรมของนิรันศักดิ์ บุญจันทร์, ศุภิสรา เทียนสว่างชัย

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์ฉบับนี้มีจุดประสงค์เพื่อศึกษาวิเคราะห์งานเขียนของนิรันศักดิ์ บุญจันทร์ ภายใต้กรอบแนวคิดนิเวศสำนึก โดยมุ่งศึกษาบทบาทและภาพแทนของธรรมชาติและมนุษย์ที่ผู้เขียนใช้นำเสนอ เพื่อแสดงให้เห็นความสัมพันธ์ที่ดำเนินไปภายใต้บริบทสังคมที่เปลี่ยนแปลงไปในด้านต่างๆ จากการศึกษาพบว่า วรรณกรรมของนิรันศักดิ์ บุญจันทร์นำเสนอแนวคิดนิเวศสำนึกที่แสดงให้เห็นปัญหาทางธรรมชาติและสิ่งแวดล้อม โดยการนำเสนอความสัมพันธ์ระหว่างธรรมชาติกับมนุษย์ที่ตั้งอยู่บนความเหลื่อมล้ำภายใต้โลกที่ยึดมนุษย์เป็นศูนย์กลาง ซึ่งภาพแทนของธรรมชาติมักจะถูกนำเสนอให้มีลักษณะเป็นคู่ตรงข้ามกับแนวคิดหรือวิวัฒนาการทางด้านต่างๆ ของมนุษย์ และมีการปฏิสัมพันธ์ในเชิงอำนาจอยู่ตลอดเวลา ภาพแทนของธรรมชาติมักถูกทำให้อ่อนแอและยอมจำนนเพื่อแสดงให้เห็นบทบาทของมนุษย์ในฐานะผู้ควบคุม เปลี่ยนแปลง กำหนดคุณค่าและความหมายให้กับธรรมชาติ จนนำไปสู่การเปลี่ยนแปลงทางธรรมชาติและวิกฤตสิ่งแวดล้อม ซึ่งปัญหาเหล่านี้ล้วนเกิดจากความสัมพันธ์ระหว่างธรรมชาติกับมนุษย์ที่ไม่สมดุลและความเพิกเฉยของมนุษย์ที่ยึดเอาตัวเองเป็นศูนย์กลาง นอกจากนี้ งานเขียนของนิรันศักดิ์ยังนำเสนอแนวคิดเชิงอนุรักษ์ที่อยู่ภายใต้กระบวนทัศน์แบบองค์รวม นำเสนอให้เห็นถึงบทบาทและความสำคัญของธรรมชาติผ่านผลกระทบจากวิกฤตสิ่งแวดล้อม โดยการใช้ฉากโลกที่ล่มสลายและหายนะที่ตกสู่มนุษย์ แสดงให้เห็นสถานะของธรรมชาติที่อยู่ในบทบาทของผู้ควบคุมการดำรงอยู่ของมนุษย์ ในขณะเดียวกัน พื้นที่ธรรมชาติยังเป็นพื้นที่แห่งการเยียวยาฟื้นฟูชีวิตและสภาพจิตใจของมนุษย์และสังคมให้หลุดพ้นจากการครอบงำของความเจริญ รวมไปถึงการตระหนักถึงตัวตนแห่งธรรมชาติที่ธรรมชาติมีบทบาทสำคัญในการประกอบสร้างตัวตนและจิตวิญญาณของมนุษย์ แสดงให้เห็นความสัมพันธ์ของมนุษย์และธรรมชาติที่เชื่อมโยงกันทั้งทางกายภาพและทางจิตวิญญาณ เป็นการแสดงแนวคิดการมองธรรมชาติแบบองค์รวมเพื่อกระตุ้นให้ตระหนักถึงความสำคัญของธรรมชาติและสิ่งแวดล้อมอันนำไปสู่การปลูกฝังแนวคิดเชิงอนุรักษ์และการอยู่ร่วมกับธรรมชาติอย่างสันติ

Integrated Learning Programme 2016-2017 : Term 2, Student Services Centre

ILP Guidebook

This Integrated Learning Programme (ILP) guidebook provides details about ILP courses offered during 2016-2017 second term in Lingnan University, Hong Kong.

Vector Competence And Correlation Of Midgut Microbiota Of Aedes Albopictus For Chikungunya Virus, Ranida Tuanudom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Chikungunya virus (CHIKV) is an important mosquito-borne virus and transmission cycle of this virus involves mosquito vectors (Aedes albopictus and Aedes aegypti) and infected vertebrate hosts. The recently studies found that CHIKV outbreak in 2007 have been Ae. albopictus as an important vector which it was susceptible to genetic variation of CHIKV and induce to virus virulence. However, the study about vector competence for CHIKV in Thailand is limited. Moreover, the previous study indicates the impact of midgut microbiota of mosquito to viral infection. This study was conducted to examine the effects of CHIKV titers in blood meals on vector …

The Effectiveness Of Betel Leaf (Piper Betle Linn) Extract Gel And Cocoa Bean (Theobroma Cacao L) Extract Gel Application Against The Hardness Of Enamel Surface In Vitro, Juni J. Nugroho, Wirna R. Hafsari

Journal of Dentomaxillofacial Science

No abstract provided.

Co-Constructing Food Access Issues: Older Adults In A Rural Food Environment In West Virginia Develop A Photonarrative, Lauri Andress, Sunah Hallie

Faculty & Staff Scholarship

This photovoice study examined the hypothesis that photos and narratives produced by older adults would facilitate the co-construction of a shared narrative about the food access issues in a rural county in West Virginia. For older adults, living in rural areas, several factors decrease access to healthy, nutritious food relative to the general population of older adults. Methods: Qualitative data from interviews, written narratives, dialogues, and photos from older adults living in a rural county of West Virginia. Was collected. Using directed content analysis, transcripts of written data were broken down into meaningful quote segments. All written data and …

Forgetting Health Disparities: A One Size Fits All Narrative, Lauri Andress

Faculty & Staff Scholarship

This qualitative synthesis explores a public health narrative and events in the US that may have contributed to the prominence of a one-size-fits all communications frame and public health tool that excludes the significance of social status. An analysis of past events is used to carry out a textual analysis of two communications framing studies. One central narrative is found to be more effective than other potential themes on equality, social conditions, and health inequities. The potential impacts of this narrative on disadvantaged, older communities are explored. Consequently, the current claim that the built-environment narrative is “good for everyone” is …

Efficacy Of Nutritional Interventions To Lower Circulating Ceramides In Young Adults: Fruvedomic Pilot Study, Alice T. Matthews, Oluremi A. Famodu, Melissa D. Olfert, Pamela J. Murray, Christopher F. Cuff, Marianne T. Downes, Norman J. Haughey, Sarah E. Colby, Paul D. Chantler, I. Mark Olfert, Joseph W. Mcfadden

Faculty & Staff Scholarship

The 2010 USDA Dietary Guidelines for Americans (DGA) recommends a diet largely composed of fruit and vegetables. Consuming a diet high in fruit and vegetables and low in refined carbohydrates and saturated fat may reduce an individual’s risk for type 2 diabetes, nonalcoholic fatty liver disease, low-grade chronic inflammation, and metabolic syndrome (MetS). Several recent studies have implicated the bioactive sphingolipid ceramide as an associative and causative biomarker for the development of these conditions. Considering that the intake of fruit and vegetables is frequently inadequate in young adults, we performed a pilot investigation to assess the efficacy of a free-living …

Analysis Of Transient Hypermorphic Activity Of E(Spl)D During R8 Specification, Adam T. Majot, Ashok P. Bidwai

Faculty & Staff Scholarship

Drosophila atonal (ato) is required for the specification of founding R8 photoreceptors during retinal development. ato is regulated via dual eye-specific enhancers; ato-3’ is subject to initial induction whereas 5’-ato facilitates Notch-mediated autoregulation. Notch is further utilized to induce bHLH repressors of the E(spl) locus to restrict Ato from its initial broad expression to individual cells. Although Notch operates in two, distinct phases, it has remained unclear how the two phases maintain independence from one another. The difference in these two phases has attributed to the hypothesized delayed expression of E(spl). However, immunofluorescence data indicate that E(spl) are expressed during …

Periodontal Status And Quality Of Life: Impact Of Fear Of Pain And Dental Fear, Casey D. Wright, Daniel W. Mcneil, Cierra B. Edwards, Richard J. Crout, Katherine Neiswanger, John R. Shaffer, Mary L. Marzita

Faculty & Staff Scholarship

Background. Oral health-related quality of life (OHRQoL) is impacted by periodontal disease and orofacial pain. There is a limited research examining the impact of avoidance of care or physiological arousal related to the fear of pain response on periodontal-related OHRQoL. Methods. Data are from the Center for Oral Health Research in Appalachia family-based study focusing on 1,339 adults. Measures included a modified Periodontal Screening and Recording Index across sextants of dentition, dental fear survey, Fear of Pain Questionnaire-9, and Oral Health Impact Profile-14. Structural equation modeling was used to estimate the effects of periodontal disease screening indicators on OHRQoL including …

Room Temperature Ferroelectricity In Fluoroperovskite Thin Films, Ming Yang, Amit Kc, A C Garcia-Castro, Pavel Borisov, E Bousquet, David Lederman, Aldo H. Romero, Cheng Cen

Faculty & Staff Scholarship

The NaMnF3 fluoride-perovskite has been found, theoretically, to be ferroelectric under epitaxial strain becoming a promising alternative to conventional oxides for multiferroic applications. Nevertheless, this fluoroperovskite has not been experimentally verified to be ferroelectric so far. Here we report signatures of room temperature ferroelectricity observed in perovskite NaMnF3 thin films grown on SrTiO3. Using piezoresponse force microscopy, we studied the evolution of ferroelectric polarization in response to external and built-in electric fields. Density functional theory calculations were also performed to help understand the strong competition between ferroelectric and paraelectric phases as well as the profound influences of strain. These results, …

Nature Of Magnetic Ordering In Cobalt‐Based Spinels, Subhash Thota, Sobhit Singh

Faculty & Staff Scholarship

In this chapter, the nature of magnetic ordering in cobalt‐based spinels Co3O4, Co2SnO4, Co2TiO4, and Co2MnO4 is reviewed, and some new results that have not been reported before are presented. A systematic comparative analysis of various results available in the literature is presented with a focus on how occupation of the different cations on the A‐ and B‐sites and their electronic states affect the magnetic properties. This chapter specifically focuses on the issues related to (i) surface and finite‐size effects in pure Co3O4, (ii) magnetic‐compensation effect, (iii) co‐existence of ferrimagnetism and spin‐glass‐like ordering, (iv) giant coercivity (HC) and exchange bias …

Exploring The Gender Gap In The Conceptual Survey Of Electricity And Magnetism, Rachel Henderson, Gay Stewart, John Stewart, Lynnette Michaluk, Adrienne Traxler

Faculty & Staff Scholarship

The “gender gap” on various physics conceptual evaluations has been extensively studied. Men’s average pretest scores on the Force Concept Inventory and Force and Motion Conceptual Evaluation are 13% higher than women’s, and post-test scores are on average 12% higher than women’s. This study analyzed the gender differences within the Conceptual Survey of Electricity and Magnetism (CSEM) in which the gender gap has been less well studied and is less consistent. In the current study, data collected from 1407 students (77% men, 23% women) in a calculus-based physics course over ten semesters showed that male students outperformed female students on …

Novel Possibilities For The Treatment And Prevention Of Cutaneous Leishmaniasis, Eva A. Iniguez

Open Access Theses & Dissertations

Protozoan parasites from the genus Leishmania cause broad clinical manifestations known as leishmaniasis, which affect millions of people worldwide. Cutaneous leishmaniasis (CL) is mainly caused by either Leishmania major or L. tropica parasites, which produce localized cutaneous ulcers, often leading to scarring and social stigma. Currently, the disease has reached hyperendemicity levels in the Middle East due to conflict and human displacement and is one the most common forms of the disease in the Old World. Furthermore, the first choice of treatment in that region continues to be pentavalent antimonials, which are costly and highly toxic, and current vector control …

Instilling Positive Beliefs About Organ Donation: An Information Processing Approach, Gerardo Jose Moreira

Open Access Theses & Dissertations

The number of those seeking a kidney donation in the United States continues to increase while the number of donors is not growing at the same rate (U.S. Department of Health and Human Services USDHHS, 2010). The lack of donations is more prevalent in low health literate communities which suffer from misinformation and ultimately negative beliefs toward organ donation. Thus, it is important to understand how marketing efforts can effectively change individuals' beliefs about organ donation.

Drawing on the Self-Determination Theory and Schema Theory, I proposed that the effectiveness of health education programs, which is to motivate individuals to be …

Place-In-Process In Colm Toíbín’S The Blackwater Lightship: Emotion, Self-Identity, And The Environment, Nancy Easterlin

English Faculty Publications

No abstract provided.

Trend Analysis In Rainfall, Reference Evapotranspiration And Aridity Index In Southern Senegal: Adaptation To The Vulnerability Of Rainfed Rice Cultivation To Climate Change, Komlan Koudahe, Koffi Djaman, Ansoumana Bodian, Suat Irkmak, Mamadou Sall, Lamine Diop, Alpha B. Balde, Daran Rudnick

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rainfall and evapotranspiration are two vital elements for food production under rainfed agriculture. This study aims at investigating the combined changes in these variables in the form of aridly index in the southern Senegal. The temporal trends in annual and monthly (from May to October) aridity index, rainfall and evapotranspiration are examined and adaptation strategies to the vulnerability of rainfed rice cultivation to the changes are developed. The results show a significant decreasing trend in annual rainfall at all study locations for the period 1922-2015. When analyzing the trends in sub-periods, there are two clear patterns in the annual rainfall …

Pollen-Mediated Gene Flow From Glyphosate-Resistant Common Waterhemp (Amaranthus Rudis Sauer): Consequences For The Dispersal Of Resistance Genes, Debalin Sarangi, Andrew J. Tyre, Eric L. Patterson, Todd A. Gaines, Suat Irmak, Stevan Z. Knezevic, John L. Lindquist, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Gene flow is an important component in evolutionary biology; however, the role of gene flow in dispersal of herbicide-resistant alleles among weed populations is poorly understood. Field experiments were conducted at the University of Nebraska-Lincoln to quantify pollen-mediated gene flow (PMGF) from glyphosate-resistant (GR) to -susceptible (GS) common waterhemp using a concentric donorreceptor design. More than 130,000 common waterhemp plants were screened and 26,199 plants were confirmed resistant to glyphosate. Frequency of gene flow from all distances, directions, and years was estimated with a double exponential decay model using Generalized Nonlinear Model (package gnm) in R. PMGF declined by 50% …

Estimating Yield Gaps At The Cropping System Level, Nicolas Guilpart, Patricio Grassini, Victor O. Sadras, Jagadish Timsina, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the cropping system yield potential as the output from the combination of crops that gives the highest energy yield per unit of land and time, and the cropping system yield gap as the difference between actual energy yield of an existing cropping system …

Modeling Pollen-Mediated Gene Flow From Glyphosate-Resistant To -Susceptible Giant Ragweed (Ambrosia Trifida L.) Under Field Conditions, Zahoor A. Ganie, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

A field experiment was conducted to quantify pollen mediated gene flow (PMGF) from glyphosateresistant (GR) to glyphosate-susceptible (GS) giant ragweed under simulated field conditions using glyphosate resistance as a selective marker. Field experiments were conducted in a concentric design with the GR giant ragweed pollen source planted in the center and GS giant ragweed pollen receptors surrounding the center in eight directional blocks at specified distances (between 0.1 and 35 m in cardinal and ordinal directions; and additional 50 m for ordinal directions). Seeds of GS giant ragweed were harvested from the pollen receptor blocks and a total of 100,938 …

Gene Silencing Of Argonaute5 Negatively Affects The Establishment Of The Legume-Rhizobia Symbiosis, Maria Del Rocio Reyero-Saavedra, Zhenzhen Qiao, Maria Del Socorro Sanchez-Correa, M. Enrique Diaz-Pineda, Jose L. Reyes, Alejandra A. Covarrubias, Marc Libault, Oswaldo Valdes-Lopez

Department of Agronomy and Horticulture: Faculty Publications

The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also …

Pseudomonas Aeruginosa And Its 4 Arsenal Of Proteases: Weapons 5 To Battle The Host, A.C.M. Galdino, M.H.B Branquinha, A.L.S. Santos, L. Viganor

Books/Book chapters

Pseudomonas aeruginosa is a ubiquitous and opportunistic human pathogen that 12 represents a critical problem to the clinician due to the increased number of 13 resistant strains isolated from hospital settings. In addition, there is a great 14 variety of pathologies associated with this versatile Gram-negative bacterium. 15 P. aeruginosa cells are able to produce an incredible arsenal of virulence factors, 16 especially secreted molecules that act singly or together to ensure the 17 establishment, maintenance, and persistence of a successful infection in 18 susceptible hosts. In this context, pseudomonal proteases roles are highlighted 19 due to their ability to …

Uv-A And -B Blocking Agents For Psoriasis Phototherapy, Sruangsuda Mawaha

Chulalongkorn University Theses and Dissertations (Chula ETD)

UV-A and -B blocking agents are essential components for the formulation of topical cream for psoriasis phototherapy. In this research, many natural compounds were discovered as potent UV-A and UV-B blocking agents, but small number could absorb narrowband UV-B. Quercetin hydrate, oxyresveratrol and curcumin were good UV-A blocking agents, while catechin, hesperetin, lutein and naringenin were proper for UV-B blocking agents. Berberine chloride hydrate, demethoxycurcumin and mansonone G were UV-A and -B blocking agents. From random combination, the mixture of mansonone G 0.010 % w/v and quercetin hydrate 0.0025 % w/v was disclosed to be a right choice for this …

Bioactive Compounds With An Inhibitory Activity Against Osteoclast Differentiation And Mechanisms, Supatta Chawalitpong

Chulalongkorn University Theses and Dissertations (Chula ETD)

โรคกระดูกพรุนเป็นปัญหาสุขภาพที่สำคัญอย่างหนึ่งของสังคมผู้สูงอายุ สาเหตุหลักของภาวะดังกล่าวเกิดจากความไม่สมดุลของเซลล์ที่ทำหน้าทีสร้างกระดูก (osteoblast) และเซลล์ที่ทำหน้าที่สลายกระดูก (osteoclast) การลดลงของมวลกระดูกในผู้สูงอายุนำมาซึ่งความเสี่ยงในการแตกหักของกระดูก จุดประสงค์ของการศึกษาครั้งนี้ คือ การคัดกรองสารออกฤทธิ์ทางชีวภาพที่มีฤทธิ์ในการต้านการเปลี่ยนสภาพของเซลล์สลายกระดูกและกลไกการออกฤทธิ์ของสารนั้นๆ ในกลุ่มสารทดสอบอนุพันธ์สาร (3S)-1-(3,4-dihydroxyphenyl)-3-hydroxy-7-phenyl-(6E)-6-heptene (DHPH) และ กรดไซเปอเรโนอิก (Cyperenoic acid) ซึ่งสกัดได้จากส่วนเหง้า Curcuma comosa Rox. และราก Croton crassifolius Geiseler. ตามลำดับ มีฤทธิ์แรงในการต้านการเกิดเซลล์สลายกระดูก ในระดับ in vitro ใช้เซลล์จากไขกระดูกที่ถูกกระตุ้นด้วย receptor activator of nuclear factor-κB ligand (RANKL) DHPH มีฤทธิ์ในการยับยั้งการเปลี่ยนสภาพไปเป็นเซลล์สลายกระดูก โดยยับยั้งการเกิด TRAP-positive multinucleated cells (TRAP+ MNCs) ที่ระดับความเข้มข้นยับยั้งกึ่งหนึ่ง (IC50) 325±1.37 นาโนโมลาร์ การยับยั้งดังกล่าวสอดคล้องกับการลดต่ำลงของสัญญาณภายใต้การกระตุ้นของ RANKL โดยรวมถึงวิถี Mitogen-activated protein kinases (MAPKs) เช่น ERK (p44/42) และ p38 แต่ไม่มีผลต่อวิถี NF-κB โดยผลของสารดังกล่าวยังส่งผลกระทบต่อระดับของ transcription factor เช่น nuclear factor of activation T cells (NFATc1) และ c-Fos ซึ่งมีความสำคัญมากในการเปลี่ยนสภาพเป็นเซลล์สลายกระดูก DHPH ลดการกัดกร่อนกระดูก (bone resorption) บนแผ่นกระดูก (bone slices) นอกจากนั้นสาร DHPH ยังสามารถเพิ่มกิจกรรมของเอนไซม์ alkaline phosphatase (ALP) ที่เกี่ยวข้องกับการเปลี่ยนสภาพของเซลล์สร้างกระดูกในเซลล์ชนิด MC3T3-E1 ในกรณีของกรดไซเปอเรโนอิกนั้น พบว่าสามารถลดการเกิด TRAP+ MNCs ที่ระดับความเข้มข้น IC50 ที่ 36.69±1.02 …