Chemistry Commons^™

Exploiting Quadratic Unconstrained Binary Optimization And Column Generation For Solving Vehicle Routing Problem With Discretized Time Windows, Krittin Phornsiricharoenphant

Chulalongkorn University Theses and Dissertations (Chula ETD)

No abstract provided.

Synthesis Of Novel 5-Aryl 2’-Deoxyuridine And 2’-Deoxycytidine Analogues, Kevin E. Persaud

Dissertations and Theses

Briefly, the following report details a synthetic route to prepare 5-phenyl-2’-deoxycytidine analogues. This multistep synthesis began with silyl protection of the 3’- and 5’-hydroxyl groups of 5-iodo-2’-deoxyuridine. Next, the installation of a phenyl ring at the C5 position of the nucleobase via a Suzuki-Miyaura cross-coupling reaction, yielding 5-phenyl-2’-deoxyuridine (5-PdU). After that, modification of the obtained 5-PdU at the C4 position was performed with benzotriazole-1-yl-oxy-tris-(dimethylamino)-phosphonium hexafluorophosphate (BOP, a peptide-coupling agent) and a base (cesium carbonate) to activate the amide group of the uridine nucleobase for subsequent displacement with a variety of amines. Modification of the C4 position resulted in protected 5-phenyl-2’-deoxycytidine …

Unlv Title Iii Aanapisi & Mcnair Scholars Institute Research Journal 2024, Jesica Godinez-Paredes, Kian Hassankhan, Apia Hickman, Robin Ruth Kee, Kevin Ayala Pineda, Briana Melendez, Kalli Ramos, Saturn L. Reyes, Fabian Leija, Selena Pepe, Silva Topchyan, Celeste Ainsley, Mayra Arzate, Jessica Balistreri, Zantana Ephrem, Mirella Jasso, Karl Panou, Nichole Pelaez, Miklo Alcala, Akshay Dave, Mey Mey Heng, Michael Finkle, Janessa Montenegro, Reynafe Naol Aniga, Victor Mejia, Angelica G. Diaz, Anayeli Flores-Garibay, Kari Lee Joe Goold, Samantha Hernandez, Lianelys Cabrera Martinez, Caitlin Reynolds, Kimberly N. Usbeck, Abdulrahman Alahdal, Angelica Diaz, Willaine Mae Kahano, Raquel Jackson, Cecia Ruiz-Hernandez, Kers Ung-Watson, Yessenia Henriquez, Vanessa Marie Booth, Alexia Brown, Darlyn Magana, Bianca Navarro, Nicholas Pereira, Gia Renemae Calip, Lucky Heng, Ralph Sagun, Lucas Abreu, Alexandra Maria Acosta, Tristan Benally, Cosset Hernandez Pena, Adrian Montenegro, Cierra Paaaina-Daquioag, Nicole Torosian, Tracy Fuentes, Julissa Martinez, Medina Mcallister, Michal Newhouse-Van Vlerin, Tiria Carr, Nima Abkenar, Isabella Aceituno, Yuhan Bi, Victoria Campos, Melika Cummings, Zachary J. Johnigan, Alexis Sotolongo-Marin

McNair Journal

Journal articles based on research conducted by undergraduate students in the AANAPISI, LSAMP, and McNair Scholars Program.

Table of Contents

About AANAPISI

Dr. Chris Heavey, Interim President

Dr. Keith Rogers, Vice President for Student Affairs

Ms. Zhanna Aronov, Associate Vice President for Retention & Outreach

Volume 15, Connor Thompson, Emily Steffenhagen, Emily Robertson, Luis Fernando Dos Reis, Emily Farmer, Samuel Villa, Robert Allison, Zachary Chessor, Megan Borden, Austin Burnett, Larry W. Grant Jr., Tristan Marowski, Emma Moore, Pearl Siff

Incite: The Journal of Undergraduate Scholarship

Introduction Dr. Amorette Barber, Director, Office of Student Research

From the Editor Dr. Hannah Dudley-Shotwell

Artist’s Statement Connor Thompson

On Mentorship Dr. John Miller

The Meat of the Matter: Alien, Human, and Animal in Terry Bisson’s “They’re Made Out of Meat” by Emily Steffenhagen

“Please REBLOG!”: An Ethical Analysis of Doxxing, Internet Vigilantism and Racists Getting Fired by Emily Robertson

Journaling: Paper Has More Patience Than People by Luis Fernando Dos Reis

The Effects of Climate Change on the Archaeological World by Emily Farmer

Lowered Seat Height Does Not Impair Wingate Performance in Untrained Cyclists by Samuel Villa, Robert Allison, …

Molecular Understanding And Design Of Deep Eutectic Solvents And Proteins Using Computer Simulations And Machine Learning, Usman Lame Abbas

Theses and Dissertations--Chemical and Materials Engineering

Hydrophobic deep eutectic solvents (DESs) have emerged as excellent extractants. A major challenge is the lack of an efficient tool to discover DES candidates. Currently, the search relies heavily on the researchers’ intuition or a trial-and-error process, which leads to a low success rate or bypassing of promising candidates. DES performance depends on the heterogeneous hydrogen bond environment formed by multiple hydrogen bond donors and acceptors. Understanding this heterogeneous hydrogen bond environment can help develop principles for designing high performance DESs for extraction and other separation applications. This work investigates the structure and dynamics of hydrogen bonds in hydrophobic DESs …

Chemical Synthesis Of Sensitive Dna, Komal Chillar

Dissertations, Master's Theses and Master's Reports

Over the past decades, researchers have tried various chemical methods to synthesize modified oligodeoxynucleotides (ODNs, i.e. short segments of DNAs). Traditional ODN synthesis methods require strong basic, and nucleophilic conditions for the deprotection and cleavage of the ODN from the solid support. However, the sensitive ODNs containing labile functionalities are vulnerable to such harsh conditions. Sensitive ODNs have a wide range of applications in research and pharmaceuticals. To synthesize sensitive ODNs, researchers devised different strategies but no practical methods have been developed. To overcome these challenges, we developed alkyl Dim alkyl Dmoc technology. This innovative technology uses weakly basic and …

Inhaling The Unseen: Exploring The Presence Of Microplastics In The Human Respiratory Tract, Kara Coffman-Rea

Graduate Research Theses & Dissertations

Microplastics (plastic pieces less than 5 mm) have emerged as a pervasive form of pollution acknowledged as a universal threat to both environmental and human health. Their small size and widespread distribution pose significant risks to marine life, terrestrial ecosystems, and ultimately human health. Microplastics have been reported in food and drink items designated for human consumption, in cosmetics and consumer goods designed for human use, and within the air we breathe, each providing an entry route for microplastics to enter the human body. Recently, microplastic particles have been detected in a variety of human tissue samples (e.g., lung tissue). …

Synthetic Strategies Toward The Development Of Stable Gold-Based Anticancer Agents And Their Mechanistic Insight, Adedamola Arojojoye

Theses and Dissertations--Chemistry

Despite notable advancements in the design and synthesis of novel chemotherapeutic drugs, cancer continues to be a leading cause of death in the United States. Metallodrugs, especially Au complexes, have played a prominent role in the search for the next generation of chemotherapeutic agents. Herein, I report on the synthetic strategies towards the rational design of stable Au (Au)-based agents, study their reactivity in biological environment, and offer insights into the cytotoxic mechanism of action in cancer. Chemotherapeutic Au compounds exist mainly in +I or +III oxidation states. Repurposing of the Au(I) FDA approved auranofin for the treatment of diseases …

Pathology And Diagnosis In Inflammatory-Related Diseases: Covid-19 And Age-Related Macular Degeneration, Zane Russell Lacasse

Graduate Research Theses & Dissertations

Chronic inflammation and dysfunctional inflammatory responses are believed to be contributing factors to the severity of many diseases. Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it has been recognized that levels of inflammatory markers and the severity of coronavirus disease-2019 (COVID-19) cases are closely related. The work within this dissertation begins with establishing an alternative platform for the diagnosis of COVID-19 and explores ways to enhance the diagnostic utility of this platform. An alternative route for COVID-19 diagnosis was explored using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS). The platform utilizes a non-invasive sampling technique …

Dna I-Motifs: Biophysical Characterization And Structure-Property Correlation As Foundation For Functional Material Design, Alexander Minasyan

Graduate Research Theses & Dissertations

Over the past decades, nucleic acids have emerged as crucial frameworks with significance in biological systems and functional material engineering. Cytosine-rich deoxyribonucleotide sequences can form quadruplex structures a.k.a. i-motifs. Recently, i-motifs have attracted scientific interest in biological and material design areas.

In this work, we systematically investigate an effect of structured and unstructured modifications such as hairpins, stems, loops and overhangs on the kinetic and thermodynamic properties of DNA i-motifs. We demonstrate that the modifications can influence i-motif’s stability and folding/unfolding rates: thus, double stranded stems and hairpins are the best at stabilizing i-motifs and increasing kinetic rates of folding. …

Photoluminescence Switching In Quantum Dots Connected With Fluorinated And Hydrogenated Photochromic Molecules, Ephraiem S. Sarabamoun, Jonathan M. Bietsch, Pramod Aryal, Amelia G. Reid, Maurice Curran, Grayson Johnson, Esther H. R. Tsai, Charles W. Machan, Guijun Wang, Joshua J. Choi

Chemistry & Biochemistry Faculty Publications

We investigate switching of photoluminescence (PL) from PbS quantum dots (QDs) crosslinked with two different types of photochromic diarylethene molecules, 4,4'-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (1H) and 4,4'-(1-perfluorocyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (2F). Our results show that the QDs crosslinked with the hydrogenated molecule (1H) exhibit a greater amount of switching in photoluminescence intensity compared to QDs crosslinked with the fluorinated molecule (2F). With a combination of differential pulse voltammetry and density functional theory, we attribute the different amount of PL switching to the different energy levels between 1H and 2F molecules which result in different potential barrier …

Hybridization And Duplex Stability Of Peptide Nucleic Acid Containing An Azobenzene Switch, Carmen J. Velasquez

College of Graduate Studies: Theses & Dissertations

Light-driven molecular switches that can be turned on and off on demand have found many biological applications. For DNA, RNA, and synthetic derivatives, the switch can be used to interfere with a hybridization event with a complementary strand. To explore this potential, we have synthesized three light-sensitive PNA which have an azobenzene group (PNA-5azo5 and PNA-4azo4), and two azobenzene groups (PNA-2azo5azo2) as part of the PNA backbone. UV experiments were used to verify the conversion to the cis-isomer from the initial trans state for all of the single-stranded Azo-PNA ( PNA-5azo5, PNA-4azo4, and PNA-2azo5azo2) by irradiating at 365 nm …

การศึกษาความเป็นไปได้ในการประยุกต์ใช้น้ำเสียที่ผ่านการบำบัดในกระบวนการอบยาง, สิรวิชญ์ โพธิ์ระหง

Chulalongkorn University Theses and Dissertations (Chula ETD)

บริษัท สยามมิชลิน จำกัด (โรงงานพระประแดง) จังหวัดสมุทรปราการ มุ่งมั่นในการจัดการทรัพยากรน้ำอย่างมีประสิทธิภาพและยั่งยืนในกระบวนการผลิตยางรถยนต์ การผลิตยางรถยนต์และยางรถจักรยานยนต์มีการใช้น้ำจำนวนมากในกระบวนการผลิต จึงเป็นเหตุให้เกิดน้ำเสียจำนวนมากตามมาเช่นกัน น้ำเสียเหล่านี้จะถูกส่งเข้าระบบบำบัดน้ำเสียแบบเลี้ยงตะกอนเร่งเพื่อบำบัดและมีสมบัติได้ตามมาตรฐานน้ำทิ้ง แนวทางในการลดการปล่อยน้ำเสียหลังการบำบัดแล้วสู่สาธารณะ คือ การนำน้ำเสียที่ผ่านการบำบัดเหล่านี้กลับมาใช้เพื่อสามารถหมุนเวียนทรัพยากรให้กลับมาใช้ใหม่อย่างมีประสิทธิภาพสูงสุด และยังสอดคล้องกับแผนการบริหารด้านความยั่งยืนในการจัดการสิ่งแวดล้อมของบริษัทอีกทางหนึ่งด้วย ในงานวิจัยนี้จึงศึกษาความเป็นไปได้ในการนำน้ำเสียที่ผ่านการบำบัดแล้วกลับมาใช้ใหม่ในกระบวนการอบยาง โดยศึกษาและปรับปรุงประสิทธิภาพอัตราการไฟล (%Recovery) ของระบบรีไซเคิลรีเวอร์สออสโมซิสแบบขั้นตอนเดียวด้วยสารกรองแก้ว (AFM®ng) พบว่ามีประสิทธิภาพเพิ่มขึ้นจากเป็นร้อยละ 64 จากนั้นศึกษาเปรียบเทียบความเป็นไปได้ของโครงการระหว่างระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO) มีร้อยละผลตอบแทนของโครงการ (%ROI) และระยะเวลาคืนทุน (Payback period) เท่ากับ ร้อยละ 242, 1.22 ปีและระบบรีไซเคิลแบบสองขั้นตอนร่วมกับระบบการกรองระดับอัลตร้า (UF-RO/RO) เท่ากับร้อยละ 189, 1.97 ปีตามลำดับ แสดงให้เห็นว่าระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO) มีผลตอบแทนด้านการลงทุน (ROI) ที่ดีที่สุด และระยเวลาการคืนทุนที่เร็วกว่า แม้ว่าระบบรีไซเคิลแบบสองขั้นตอนร่วมกับระบบการกรองระดับอัลตร้า (UF-RO/RO) จะมีคุณภาพน้ำดีกว่า แต่เมื่อพิจารณาต้นทุนแล้ว พบว่าไม่แตกต่างกันมากนัก เนื่องจากระบบรีไซเคิลแบบสองขั้นตอน (Double-pass RO)มีร้อยละผลตอบแทนการลงทุนที่ดีที่สุด และระยะเวลาคืนทุนเร็วกว่า บริษัทฯ จึงเลือกใช้ระบบนี้ในการผลิตน้ำป้อนเข้าสู่หม้อต้มไอน้ำ ส่งผลให้สัดส่วนการใช้น้ำประปาในการอบยางลดลงร้อยละ 26 สัดส่วนการใช้น้ำรีไซเคิลเพิ่มขึ้นถึงร้อยละ 42 และลดการปลดปล่อยก๊าซคาร์บอนไดดอกไซด์ได้ 111.63 ตันคาร์บอนไดออกไซด์ต่อปี

การประเมินคาร์บอนฟุตพริ้นท์องค์กรและการลดก๊าซเรือนกระจกภายใต้โครงการสนับสนุนกิจกรรมลดก๊าซเรือนกระจก: กรณีศึกษาโรงงานผลิตยางคอมพาวด์, ปภาวรินท์ ทรงพัฒนาศิลป์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัญหาการเปลี่ยนแปลงสภาพภูมิอากาศในปัจจุบันเกิดจากการเพิ่มขึ้นของปริมาณก๊าซเรือนกระจก ซึ่งมีความรุนแรงและมีแนวโน้มที่จะส่งผลกระทบที่เพิ่มมากขึ้น ประเทศต่าง ๆ และองค์กรทั่วโลกได้กำหนดเป้าหมายในการลดการปล่อยก๊าซเรือนกระจก จึงเป็นสิ่งสำคัญที่ต้องตระหนักถึงและแก้ไขผลกระทบที่เห็นได้ชัดจากการเปลี่ยนแปลงสภาพภูมิอากาศ เพื่อส่งเสริมความร่วมมือในการบรรเทาปัญหาอย่างมีประสิทธิภาพ การศึกษานี้มีวัตถุประสงค์เพื่อประเมินปริมาณคาร์บอนฟุตพริ้นท์องค์กรของโรงงานผลิตยางคอมพาวด์ และประเมินปริมาณการลดการปล่อยก๊าซเรือนกระจกจากกิจกรรมในองค์กร ภายใต้โครงการสนับสนุนกิจกรรมลดก๊าซเรือนกระจก (Low Emission Support Scheme: LESS) ขององค์การบริหารจัดการก๊าซเรือนกระจก (องค์การมหาชน) ในปี พ.ศ. 2565 และ 2566 ผลการศึกษาพบว่าปริมาณการปล่อยก๊าซเรือนกระจกทั้งหมดมีแนวโน้มลดลงจาก 41,675.07 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อปี ในปี พ.ศ. 2565 สู่ 38,043.30 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อปีในปี พ.ศ. 2566 โดยขอบเขตที่ 3 การปล่อยก๊าซเรือนกระจกทางอ้อมอื่นๆ มีสัดส่วนที่สูงที่สุด คิดเป็นร้อยละ 78.55 และ 79.81 ตามลำดับ รองลงมา คือ ขอบเขตที่ 2 การปล่อยจากการใช้พลังงาน มีสัดส่วนคิดเป็นร้อยละ 20.05 และ 18.40 และขอบเขตที่ 1 การปล่อยทางตรงขององค์กร มีสัดส่วนต่ำที่สุด คิดเป็นร้อยละ 1.39 และ 1.80 เมื่อวิเคราะห์ต่อยอดการผลิต พบว่า ปริมาณการปล่อยก๊าซเรือนกระจกประเภทที่ 1 และ 2 ต่อยอดผลิตในปี พ.ศ. 2565 และ 2566 เท่ากับ 0.1717 และ 0.1699 ตามลำดับ ขณะที่ปริมาณการปล่อยก๊าซเรือนกระจกขอบเขตที่ 1 2 และ 3 ต่อยอดผลิต เท่ากับ 0.8005 และ 0.8413 ตันคาร์บอนไดออกไซด์เทียบเท่าต่อตัน ผลการศึกษาในการลดก๊าซเรือนกระจกจากการดำเนินกิจกรรมภายในองค์กรสามารถลดปริมาณการปล่อยก๊าซเรือนกระจกในปี พ.ศ. 2565 และ 2566 เท่ากับ 2,255.29 ตันคาร์บอนไดออกไซด์เทียบเท่า โดยการติดตั้งระบบพลังงานหมุนเวียนจากแสงอาทิตย์ (Solar Rooftop) สามารถลดปริมาณก๊าซเรือนกระจกได้ในปี พ.ศ. 2565 …

Geochemistry Of Rare Earth Elements In Simulated Natural Waters: Experiments And Modelling Of Precipitation, Complexation, And Bioavailability., Samantha Zulian

Theses and Dissertations (Comprehensive)

Rare earth elements (REEs) are an important part of modern technology and used for many applications. Mining, agriculture, improper recycling and medical applications can increase the concentration of these elements in surface waters. Metals in the environment including REEs can be found naturally but understanding the implications increase concentrations from anthropogenic inputs is important. REE mobility, persistence and toxicity is imperative to risk assessment as Canada begins to mine REE. Ultimately, as with other metals, the impacts of REEs in the environment should be dependent on the specific physical and chemical forms of the elements. Fractionation provides a practical method …

The Investigation Of The Antimicrobial And Biofilm-Disrupting Properties Of Synthesized Hemibastadin Derivatives, Antonio Harvey, Andrew A. Yeagley

Longwood Senior Thesis Proposal

We want to investigate structural changes to the core hemibastadin structure while attempting to make these derivatives biologically safer. Since these modifications have never been done before, we will need to design a synthesis of these new molecules. Due to the nature of the molecules (dimers), a divergent synthesis that allows for the creation of both halves simultaneously seems most appropriate. A successful synthesis of these compounds will allow us to further investigate these derivatives for their antimicrobial and biofilm-disrupting properties.

Identification Of Scientific Argumentation Ability Of High School Students On Optical Instrument Material, Rais Muktamar Amin, Parno Parno, Sentot Kusairi, Marlina Ali

Jurnal Pendidikan Sains

Optical instruments play a crucial role in physics education, providing essential material for students to understand complex concepts. This study aims to evaluate the scientific argumentation abilities of high school students regarding optical instruments. Conducted as a quantitative descriptive study, the research involved 60 eleventh-grade MIPA students from SMA Laboratorium UM. The research instrument was a scientific argumentation test comprising 12 essay questions, designed according to the Toulmin Argumentation Pattern (TAP) adaptation indicators, with a reliability coefficient of 0.332. Student responses were classified into five levels of scientific argumentation based on the TAP model, as developed by Sampson, Enderle, and …

Analyzing Physics Students’ Misconceptions About Simple Electrical Circuits, Sapta Adiguna, Shinta Dewi Susanti, Sentot Kusairi, Iwan Setiawan

Jurnal Pendidikan Sains

This study investigates the prevalence and types of misconceptions among first-year Physics Education students regarding simple electrical circuits using the Simple Electric Circuits Diagnostic Test (SECDT). Employing a quantitative descriptive approach, the research analyzes responses from a sample of 42 students, selected through convenience sampling. The SECDT, a three-tier diagnostic instrument with a reliability of 0.69, identifies student misconceptions by categorizing responses into scientific knowledge, misconceptions, no understanding, and lack of knowledge. The results indicate significant gender differences in the types and prevalence of misconceptions. Male students exhibited a higher percentage of misconceptions (77.5%) compared to female students (62.8%). Notably, …

Covalent Inhibition Of Enzyme Sortase A As A New Pathway Against Bacterial Resistance Of Staphylococcus Aureus, Umyeena Bashir

Master's Theses

The continued rise of antibiotic-resistant bacteria, such as MRSA (methicillin-resistant Staphylococcus aureus), has made the discovery of novel antibiotics critical. While bacteriostatic and bactericidal antibiotics inevitably exert evolutionary pressure on bacteria to develop resistance, small molecules that target mechanisms of bacterial virulence present a promising alternative for treatment. Sortase A (Srt A), a cysteine protease of S. aureus, promotes bacterial virulence by covalently attaching proteins such as pilin to the bacterial surface, enabling bacterial adhesion to mammalian cells. Inhibitory studies of this enzyme have gained prominent interest as a new pathway for drug development since blocking this enzyme's ability to …

The Influence Of Predict, Observe, And Explain (Poe) Learning Accompanied By Formative Assessment On Misconceptions And Mastery Of Students’ Concepts Of Temperature And Heat Material, Ahmad Ilmar, Sentot Kusairi, Khusaini Khusaini

Jurnal Pendidikan Sains

High misconceptions and students’ mastery of concepts that are low enough are detected in temperature and heat material. To overcome this, teachers must apply learning strategies that are able to actively involve students in observation activities, namely the POE learning strategy. However, POE learning is not always easy to apply, students are still weak in communicating the results of their experiments. Therefore, a way is needed that helps students during the learning process to be more confident and not afraid when asked to argue, namely with formative assessment. POE learning accompanied by formative assessment aims to enable students to understand …

Identifying Students’ Incorrect Common-Sense Knowledge In Forces And Motion: Recommendations For Developing Computer-Based Learning Media, Ahmad Ridlotul Adha, Sutopo Sutopo, Nasikhuddin Nasikhuddin

Jurnal Pendidikan Sains

Conceptual understanding is a crucial area in physics education research, focusing on students’ comprehension of fundamental principles. Force and motion, integral topics within this field, are inherently linked to students’ daily experiences. Numerous studies have identified the persistence of common sense knowledge among students. This research presents a literature review aimed at identifying such consistently held misconceptions. We analyzed 17 papers sourced from Publish or Perish 8, Google Scholar, and Scopus. Our analysis revealed that the concepts of impetus and active force are the most persistent forms of common sense knowledge, influenced by real-life experiences. Additionally, students’ difficulties with kinematics …

Sustainable Food House Area (Sfha): Analysis Of Community Knowledge And Behavior, Delvi Adri, Mimien Henie Irawati, Sueb Sueb

Jurnal Pendidikan Sains

This research aimed to assess the knowledge and behavior of the community regarding the Sustainable Reserve Food Garden (SRFG) program. The study was conducted in July 2016 in Jorong Lubuk Agam, Kenagarian Ampang Kuranji Koto Baru, Dharmasraya, West Sumatra. Utilizing a descriptive quantitative approach, data were collected using Accidental Random Sampling, involving 33 heads of families as respondents. The findings revealed that community knowledge and behavior related to the SRFG program were generally insufficient, with 44.1% and 47.27% of respondents, respectively, demonstrating a lack of understanding and practice. The study concludes that approximately one-third of the population has limited knowledge …

Conversion Of Cellulose To 5-Hydroxymethylfurfural As Sustainable Energy: A Bibliometric Analysis By Vosviewer, Royyan Faradis, Ardiansyah Bagus Suryanto, Irmina Kris Murwani

Journal of Environmental Science and Sustainable Development

The developments of the global economy and society impact resources and the environment. This condition requires an alternative to find new, safe, and sustainable energy types. The conversion of cellulose to 5-hydroxymethylfurfural (5-HMF) has become a significant area of research interest. It has triggered the development of research directions related to biomass and energy because it can be an intermediary source for making polymers, solvents, pharmaceuticals, and biofuels. The primary objective of this study is to give a bibliometric analysis of 1753 reports on the development of research on cellulose conversion to 5-HMF from 1965 to 2021. The data were …

Variables Affecting The Extraction Of Antioxidants In Cold And Hot Brew Coffee: A Review, Brian Yust, Frank Wilkinson, Niny Rao

College of Life Sciences Faculty Papers

Coffee beans are a readily available, abundant source of antioxidants used worldwide. With the increasing interest in and consumption of coffee beverages globally, research into the production, preparation, and chemical profile of coffee has also increased in recent years. A wide range of variables such as roasting temperature, coffee grind size, brewing temperature, and brewing duration can have a significant impact on the extractable antioxidant content of coffee products. While there is no single standard method for measuring all of the antioxidants found in coffee, multiple methods which introduce the coffee product to a target molecule or reagent can be …

Long Oligodeoxynucleotides: Chemical Synthesis, Isolation Via Catching-By-Polymerization, Verification Via Sequencing, And Gene Expression Demonstration, Yipeng Yin, Reed Arneson, Alexander Apostle, Adikari M.D.N. Eriyagama, Komal Chillar, Emily Burke, Martina Jahfetson, Yinan Yuan, Shiyue Fang

Michigan Tech Publications

Long oligodeoxynucleotides (ODNs) are segments of DNAs having over one hundred nucleotides (nt). They are typically assembled using enzymatic methods such as PCR and ligation from shorter 20 to 60 nt ODNs produced by automated de novo chemical synthesis. While these methods have made many projects in areas such as synthetic biology and protein engineering possible, they have various drawbacks. For example, they cannot produce genes and genomes with long repeats and have difficulty to produce sequences containing stable secondary structures. Here, we report a direct de novo chemical synthesis of 400 nt ODNs, and their isolation from the complex …

Celestial Bodies, Rebecca L. Rand, Mark Popinchalk

Capstones

Most of us will never come close to touching space. But space touches us every day. On Celestial Bodies, journalist Rebecca Rand and astronomer Mark Popinchalk explore the ways outer space interacts with life on earth.

In Episode 1, hosts Rebecca Rand and Mark Popinchalk explore how, for millions of years, trees have been recording celestial events in space. Within the rings of their trunks, trees store radiation from solar flares, supernovae, and changes in the earth’s magnetic field. The hosts talk to Dr. Ben Pope to learn more about what we can discover by looking at radioactive molecules …

Mutational Analysis Of The Nitrogenase Carbon Monoxide Protective Protein Cown Reveals That A Conserved C‑Terminal Glutamic Acid Residue Is Necessary For Its Activity, Dustin L. Willard, Joshuah J. Arellano, Mitch Underdahl, Terrence M. Lee, Avinash S. Ramaswamy, Gabriella Fumes, Agatha Kliman, Emily Y. Wong, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nitrogenase is the only enzyme that catalyzes the reduction of nitrogen gas into ammonia. Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Many nitrogen fixing bacteria protect nitrogenase from CO inhibition using the protective protein CowN. This work demonstrates that a conserved glutamic acid residue near the C-terminus of Gluconacetobacter diazotrophicus CowN is necessary for its function. Mutation of the glutamic acid residue abolishes both CowN’s protection against CO inhibition and the ability of CowN to bind to nitrogenase. In contrast, a conserved C-terminal cysteine residue is not important for CO protection by CowN. Overall, this work …

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

An Inkjet-Printed Graphene Oxide–Poly(3,4-Ethylenedioxythiophene) Poly(Styrene Sulfonate) Electrode For Nitrite Detection In Water, Budi Riza Putra, Weni Anindya, Mohamad Rafi, Ika Kartika, Yudi Nugraha Thaha, Aga Ridhova, Wulan Tri Wahyuni

Makara Journal of Science

In this study, a screen-printed electrode (SPE) for nitrite (NO₂⁻) sensing was fabricated through an inkjet printing technique using a commercial printer machine and preparing an ink composite solution containing graphene oxide (GO) and poly(3,4 ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) as conductive materials. The optimum ink materials for SPE fabrication comprised GO and PEDOT:PSS with binders that resemble the viscosity of commercial ink. The surface topography of the fabricated SPE, which was characterized using scanning electron microscopy and atomic force microscopy, showed a smoother surface compared to the commercial screen-printed carbon electrode, with conductive ink materials deposited primarily …