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<title>DT - Mathematics and Natural Science</title>
<link>http://repository.ipb.ac.id/handle/123456789/90</link>
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<dc:date>2026-05-27T20:40:32Z</dc:date>
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<title>Keragaman Bakteri Ulkus Diabetikum Sebagai Upaya Pendekatan Terapi dengan Menggunakan Bakteriofag pada Luka Penderita Diabetes</title>
<link>http://repository.ipb.ac.id/handle/123456789/173087</link>
<description>Keragaman Bakteri Ulkus Diabetikum Sebagai Upaya Pendekatan Terapi dengan Menggunakan Bakteriofag pada Luka Penderita Diabetes
Ernawati, Andi
The wound microbiome plays a crucial role in the development of diabetic ulcers. Understanding the pathogenic bacteria present in diabetic ulcers is essential for identifying the types of bacteria responsible for infection. Hemolysins are important virulence factors in pathogenic infections. Diabetic wounds are susceptible to bacterial infections that are resistant to multiple drugs, complicating treatment and recovery. Therefore, understanding the microbiota profiles and resistance mechanisms is essential for effective clinical management. Molecular sequencing has also improved our understanding of the complex microbial diversity found in diabetic ulcers. Pathogenic bacteria that cause infections in diabetic wounds must be isolated and controlled using bacteriophages.&#13;
 The objectives of this study are as follows: (1) to reveal the diversity of bacteria in wound infections in patients with diabetes, both cultivable and uncultivable, through metagenomic analysis using Oxford Nanopore Technologies (ONT). This study examined the hemolytic capacity of pathogenic bacteria, antibiotic resistance, strong biofilm formation, resistance to the blaTEM gene, resistance to the sul1 gene, and identification of the 16S rRNA gene in selected isolates, and (2) the isolation, characterization, and efficiency of phages capable of infecting pathogenic bacteria from diabetic wounds in vitro.&#13;
Wound samples from each patient were cultured using Eosin Methylene Blue Agar (EMBA), Maltose Salt Agar (MSA), and Pseudomonas Cetrimide Agar. Single bacterial colonies that grew were tested for hemolytic activity. This study yielded 70 isolates with hemolytic activity; of these, 15 were identified as ß-hemolysin, 8 as a-hemolysin, and 47 as ?-hemolytic.&#13;
Fifteen bacterial isolates showed ß-haemolysin activity, dominated by Staphylococcus aureus and Pseudomonas aeruginosa. Six isolates showed a multiple antibiotic resistance (MAR) index &gt;0.4 and had the ability to form biofilms. Based on their ability to form biofilms, five bacterial isolates were classified as poor (P54A and P63AC2), weak (1PACP and 14PIBC), or moderate (bacterial isolate code 13MIPP). Bacterial isolates with weak and moderate biofilm formation abilities and a MAR index = 0.4 were proceeded to the DNA isolation stage, 16s RNA gene identification, ß-lactamase gene (blaTEM) detection, sulfonamide gene (sul1) detection, and sequencing. PCR results confirmed the presence of blaTEM and sul1 in three isolates (1PACP, 13MIPP, and 14PIBC). The three isolates identified using 16s rRNA were Pseudomonas aeruginosa 1PACP, Staphylococcus aureus 13MIPP, and Pseudomonas aeruginosa 14PIBC. These findings highlight the prevalence of multidrug-resistant and biofilm-forming bacteria in diabetic wounds, emphasising the need for targeted antimicrobial strategies and resistance monitoring.&#13;
Swab samples from each patient's wound were extracted for genomic analysis using nanopore sequencing. Samples from patients receiving antibiotics were coded 4, 7AB, and 8, whereas samples from patients not receiving antibiotics were coded 11. This study showed that the species with the highest abundance in sample 11 was Acinetobacter junii, in sample 4 was Proteus mirabilis, in sample 7AB were Alcaligenes faecalis and Pseudomonas aeruginosa, and in sample 8 was Acinetobacter baumannii. Patients who did not receive antibiotic treatment and those who did receive antibiotic treatment showed the presence of significant pathogenic microorganisms.&#13;
Staphylococcus aureus 13MIPP and Pseudomonas aeruginosa 14PIBC were selected to be controlled by bacteriophages isolated from various water sources in the environment. Bacteriophage FSA_2.2DS with host Staphylococcus aureus 13MIPP was successfully isolated, while bacteriophages with host Pseudomonas aeruginosa 14PIBC that were successfully isolated were FPA_14S6A2, FPA_14S3A, FPA_14S7A, FPA_14S8A, FPA_14S8B, and FPA_14S7E. The bacteriophages FPA_14S6A2, FPA_14S3A, FPA_14S7A, FPA_14S8A, FPA_14S8B, FPA_14S7E, and FSA_2.2DS were tested for their effectiveness against their respective specific hosts and characterised for their protein molecular weight using SDS-PAGE analysis.&#13;
SDS-PAGE analysis of the six bacteriophage isolates with the host P. aeruginosa strain 14PIBC showed protein bands, except for isolate code 4 (FPA_14S8A), which had no protein bands. Isolate code 1 (FPA_14S6A2) had three protein bands with molecular weights ranging from 59.35 kDa, 29.25 kDa, to 25.99 kDa. Isolate code 2 (FPA_14S3A) had three protein bands with molecular weights ranging from 59.35 kDa, 29.25 kDa, to 25.99 kDa. Isolate code 3 (FPA_14S7A) with three protein bands with molecular weights ranging from 59.35 kDa, 29.25 kDa, 25.99 kDa. Isolate code 5 (FPA_14S8B) with 1 band with a molecular weight ranging from 29.25 kDa. Isolate code 6 (FPA_14S7E) with two bands with molecular weights ranging from 59.35 kDa to 29.25 kDa.&#13;
The effectiveness test of bacteriophages against P. aeruginosa strain 14PIBC hosts showed that FPA_14S6A2 at 3-hour, 6-hour, and 9-hour incubations showed significantly different bacterial colony growth and a decrease in the number of bacterial colonies. Meanwhile, at 12 h of incubation, the number of bacterial colonies increased (not significantly different from 6 h of incubation), but at 24 h of incubation, there was a significant decrease in the number of bacterial colonies (105 CFU/mL) compared to the control at 24 h of incubation (1011 CFU/mL).&#13;
The test of the effectiveness of bacteriophages against the S. aureus 13MIPP host showed that FSA_2.2DS at 3 and 6 h of incubation showed significantly different bacterial colony growth and an increase in the number of bacterial colonies. Meanwhile, at 9, 12, and 24 h of incubation, the number of bacterial colonies remained constant (no significant difference), whereas at 24 h of incubation, the number of bacterial colonies was 107 CFU/mL, which was significantly different from the control at 24 h of incubation (number of bacterial colonies was 1010 CFU/mL). This indicates the potential of bacteriophages to lyse Staphylococcus aureus 13MIPP and Pseudomonas aeruginosa 14PIBC bacteria originating from wound swabs of patients with diabetes.
</description>
<dc:date>2026-01-01T00:00:00Z</dc:date>
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<item rdf:about="http://repository.ipb.ac.id/handle/123456789/173037">
<title>Potensi Ekstrak Kangkang Katup (Phanera semibifida  (Roxb.) Benth) Asal Kepulauan Lingga sebagai Kandidat Antidiabetes Baru</title>
<link>http://repository.ipb.ac.id/handle/123456789/173037</link>
<description>Potensi Ekstrak Kangkang Katup (Phanera semibifida  (Roxb.) Benth) Asal Kepulauan Lingga sebagai Kandidat Antidiabetes Baru
Suhendra, Meyla
Diabetes melitus atau DM adalah salah satu penyakit degeneratif yang dicirikan dengan tingginya kadar gula darah (hiperglikemia). International Diabetes Federation (IDF) menyatakan jumlah penderita diabetes di dunia akan terus meningkat dengan penderita terbanyak berada pada usia produktif. Indonesia menempati posisi lima besar kejadian diabetes terbanyak di dunia. Berbagai terapi diabetes terus dikembangkan termasuk penggunaan obat bahan alam. Tumbuhan yang memiliki potensi untuk dikembangkan sebagai antidiabetes adalah Kangkang katup (Phanera semibifida). Penelitian terdahulu menyatakan bahwa genus ini mampu menghambat aktifitas enzim a-glukosidase dan mampu menurunkan kadar gula darah tikus Sprague Dawley. Tumbuhan ini telah digunakan oleh masyarakat Lingga sebagai bahan baku pembuatan ramuan khas daerah tersebut. Namun, pengujian tumbuhan sebagai antidiabetes belum pernah dilakukan. &#13;
Penelitian ini merupakan tipe eksperimental dengan pendekatan multi-tahap. Tahap pertama merupakan penelitian jenis eksplorasi serta preparasi sampel kangkang katup yang diperoleh dari desa Resun, Kepulauan Lingga, provinsi kepulauan Riau. Tahap kedua adalah tahap ekstraksi, screening fitokimia dan evaluasi profil metabolit kangkang katup. Tahap ketiga adalah studi bioinformatika dengan pendekatan molecular docking dan molecular dynamic antidiabetes pada senyawa kangkang katup. Tahap keempat adalah evaluasi potensi antidiabetes dan antioksidan kangkang katup secara in vitro (IC50). Tahap kelima adalah evaluasi ekstrak kangkang katup sebagai antidiabetes pada tikus diabetes dengan desain kelompok kontrol acak dan tahap keenam adalah formulasi ekstrak kangkang katup kedalam bentuk nanoekstrak (fitosom).&#13;
Tahap pertama dari penelitian ini berhasil mengoleksi dan mengidentifikasi dua sampel kangkang katup dari kepulauan Lingga. Selanjutnya dilakukan ekstraksi dengan menggunakan lima pelarut. Berdasarkan hasil screening uji kemampuan antidiabetes dan uji toksisitas pada 20 ekstrak, ekstrak etanol Phanera semibifida (Roxb.) Benth menunjukkan hasil terbaik jika dibandingkan dengan ekstrak lainnya. ekstrak ini mengandung flavonoid, terpenoid, saponin, dan tanin. Hasil LCMS-MS menunjukkan bahwa ekstrak etanol batang memiliki 26 senyawa sedangkan ekstrak daun memiliki 24 senyawa. Selanjutnya dilakukan  pengujian in silico dengan menggunakan 4 reseptor target yaitu aldosa reduktase, a-amilase, a-glukosidase dan Sodium-Glucose Linked Transporter (SGLT). Interaksi terbaik terdapat pada Aldose reductase dan asam Alfaketoapidik, a-amilase dan Ellagic acid, a-glukosidase dan SLGT-2 memiliki interaksi terbaik dengan Cianidanol. &#13;
Penelitian tahap ketiga adalah pengujian aktifitas antidiabetes dan antioksidan  (IC50) secara in vitro. Berdasarkan pengujian ini, ekstrak etanol batang secara konsisten menunjukkan hasil yang lebih tinggi jika dibandingkan dengan ekstrak daun. sehingga berdasarkan hasil ini, ekstrak etanol batang digunakan untuk pengujian in vivo serta dapat diformulasikan ke dalam bentuk nano-ekstrak (fitosom). Hasil uji in vivo menujukkan bahwa ekstrak etanol batang kangkang katup mampu menurunkan kadar glukosa darah tikus diabetes secara signifikan pada hari ke 4 dengan nilai terendah ditunjukkan oleh kelompok dosis 400 mg/kg BB pada hari ke 16. Ekstrak batang kangkang katup juga mampu memperbaiki bobot badan tikus diabetes dan tidak memengaruhi profil hematologi pada semua perlakuan. Hasil ini juga membuktikan ekstrak batang kangkang katup mampu memperbaiki biokimia kadar darah tikus diabetes (alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea dan kreatinin)  serta memperbaiki profil lipid tikus diabetes dengan menurunkan kolesterol, trigliserida, HDL dan VLDL. &#13;
Formulasi nano-ekstrak dalam bentuk fitosom berhasil dilakukan dengan menggunakan metode thin-layer hidration. Fitosom yang dihasilkan memiliki ukuran partikel sebesar 120-300nm dan stabil hingga masa penyimpanan 3 bulan. Investigasi terhadap mekanisme kerja kangkang katup menunjukkan bahwa kangkang katup bekerja terhadap insulin, ginjal, glikogen hati dan enzim pencernaan. Kangkang katup menunjukkan potensi sebagai kandidat antidiabetes baru dan diharapkan memiliki kemampuan yang tidak lebih buruk jika dibandingkan obat sintetis; Diabetes mellitus (DM) is a degenerative metabolic disorder characterized by elevated blood glucose levels (hyperglycemia). The International Diabetes Federation (IDF) reports that the global prevalence of diabetes continues to increase, with the highest proportion of affected individuals belonging to the productive age group. Indonesia ranks among the top five countries with the highest number of diabetes cases worldwide.&#13;
Various therapeutic strategies for diabetes management have been extensively developed, including the exploration of natural product–based medicines. One plant with promising potential for development as an antidiabetic agent is Phanera semibifida (locally known as Kangkang katup). Previous studies have demonstrated that species in this genus exhibit inhibitory activity against the a-glucosidase enzyme and can reduce blood glucose levels in Sprague–Dawley rats. Furthermore, this plant has been traditionally used by the Lingga community as a primary ingredient in local herbal formulations. However, the comprehensive scientific evaluation of this plant as an antidiabetic agent remains limited.&#13;
This study was designed as an actual experimental research employing a multi-stage approach. The first stage involved exploratory research and sample preparation of Phanera semibifida (Kangkang katup), which was collected from Resun Village, Lingga Regency, Riau Islands Province, Indonesia. The second stage consisted of extraction, phytochemical screening, and metabolite profiling of Kangkang katup. The third stage involved a bioinformatics study that applied molecular docking and molecular dynamics to evaluate the antidiabetic potential of compounds identified from Kangkang katup. The fourth stage comprised in vitro evaluation of the antidiabetic and antioxidant activities of Kangkang katup extracts, including determination of IC50 values. The fifth stage involved assessment of the antidiabetic effects of Kangkang katup extract in diabetic rat models using a randomized controlled group design. The sixth stage focused on formulating Kangkang katup extract into a nano-extract delivery system (phytosome formulation).&#13;
The first stage of this study successfully collected and identified two Kangkang katup samples from the Lingga Islands, Indonesia. Subsequently, both samples were extracted using five different solvents. Based on the screening results of antidiabetic activity and toxicity assays conducted on 20 extracts, the ethanolic extract of Phanera semibifida (Roxb.) Benth demonstrated the most promising activity compared to the other extracts. Phytochemical screening revealed the presence of flavonoids, terpenoids, saponins, and tannins in this extract. LC–MS/MS analysis showed that the ethanolic stem extract contained 26 compounds, while the leaf extract contained 24 compounds. The LCMS/MS identified compounds were further subjected to in silico analysis using four receptor targets: aldose reductase, a-amylase, a-glucosidase, and sodium glucose linked transporter 2 (SGLT-2). The strongest predicted interactions were observed between aldose reductase and a-keto acid derivatives, a-amylase and ellagic acid, a-glucosidase and cianidanol, and SGLT-2 and gallic acid.&#13;
The third stage of the study involved in vitro evaluation of antidiabetic and antioxidant activities, including determination of IC50 values. Based on these assays, the ethanolic stem extract consistently showed better bioactivity than the leaf extract. Therefore, the ethanolic stem extract was selected for in vivo evaluation and for formulation into a nano-extract delivery system (phytosome). The in vivo results showed that the ethanolic stem extract of Phanera semibifida (Roxb.) Benth significantly reduced blood glucose levels in diabetic rats as early as day 4 of treatment. The most significant reduction was observed in the 400 mg/kg body weight group on day 16. In addition, the stem extract improved body weight in diabetic rats and did not adversely affect hematological parameters across all treatment groups. Consistently, the extract ameliorated biochemical markers in diabetic rats, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, and creatinine levels. Furthermore, it improved the lipid profile by reducing total cholesterol, triglycerides, HDL, and VLDL levels.&#13;
The nano-extract formulation in the form of a phytosome was successfully developed using the thin-layer hydration method. The resulting phytosomes exhibited particle sizes ranging from 120 to 300 nm and remained stable for up to three months of storage. Investigation of the mechanism of action of Phanera semibifida (Roxb.) Benth indicated that the extract exerts its effects by modulating insulin regulation, renal function, hepatic glycogen metabolism, and digestive enzymes. Overall, Phanera semibifida (Roxb.) Benth demonstrates considerable potential as a novel antidiabetic candidate and is expected to exhibit therapeutic efficacy comparable to synthetic antidiabetic drugs
</description>
<dc:date>2026-01-01T00:00:00Z</dc:date>
</item>
<item rdf:about="http://repository.ipb.ac.id/handle/123456789/172967">
<title>Human Adaptation to Risky Environments</title>
<link>http://repository.ipb.ac.id/handle/123456789/172967</link>
<description>Human Adaptation to Risky Environments
Ariyanti, Yanti
Local adaptation describes the process by which organisms develop specialized traits suited to their specific environment. In biological terms, this relationship is captured by the fundamental equation P = G + E + (G × E), where phenotype (P) represents observable characteristics emerging from dynamic interactions between genetic factors (G) and environmental influences (E). Like plants and animals, humans can develop local adaptations to particular environments, reflected in perceptual frameworks, behavioural patterns, and genetical characteristics. However, scientific evidence for local adaptation in humans remains relatively limited and underreported in the scientific literature. This study investigates human adaptation to an active volcanic environment, where generations persist despite catastrophic risk. Applying this biological framework, the research examines adaptation at the cognitive, behavioural, and genetic levels on the slopes of Mount Semeru (East Java, Indonesia).&#13;
Through a large scale lab-in-the-field experiment within this natural laboratory of recurrent volcanic risk, and by exploiting an unexpected major eruption that occurred during data collection, we compared communities in the high-risk zone with those in relatively safer areas. Our findings show that chronic exposure to volcanic hazard shapes a unique adaptive perception. Residents in the high-risk zones perceive tangible and intangible benefits that offset objective threat. This context-specific rationale forms a foundational adaptive phenotype that overrides baseline demographic differences such as gender. This study also finds that long-term exposure shapes a stable behavioural phenotype of increased individual risk aversion, while socio-cultural norms such gotong-royong (mutual assistance) maintain stable prosocial tendencies. The 2021 Semeru eruption acted as a temporary catalyst, triggering a surge in solidarity without altering this underlying caution. This pattern demonstrates a dual adaptive strategy, where persistent hazard shapes personal caution, while sudden catastrophe triggers collective solidarity.&#13;
Genetic analysis of the DRD4 gene, associated with novelty seeking, reveals a more complex picture. Although allele frequency differences were observed between zones, this genetic variation was not directly linked to financial risk taking in experiments. Instead, factor such as gender, age, number of children, and temporal context relative to the eruption showed significant associations. This suggest that the well-documented risk aversion among high-risk zone residents is not driven by simple genetic determinism.&#13;
Overall, our study demonstrates that human persistence in extreme environments is built through integrated multi-level adaptation. A uniquely calibrated perception of the landscape enables habitation, which translates into a chronic personal caution phenotype, while deeply rooted cultural norms like gotong royong ensure stable prosociality and enable a strong, flexible response to acute crises. Together, these cognitive, behavioural, and cultural layers, interacting with a complex genetic basis, constitute a comprehensive model of human resilience on an active volcano.
</description>
<dc:date>2026-01-01T00:00:00Z</dc:date>
</item>
<item rdf:about="http://repository.ipb.ac.id/handle/123456789/172966">
<title>Human Adaptation to Risky Environments</title>
<link>http://repository.ipb.ac.id/handle/123456789/172966</link>
<description>Human Adaptation to Risky Environments
Ariyanti, Yanti
Local adaptation describes the process by which organisms develop specialized traits suited to their specific environment. In biological terms, this relationship is captured by the fundamental equation P = G + E + (G × E), where phenotype (P) represents observable characteristics emerging from dynamic interactions between genetic factors (G) and environmental influences (E). Like plants and animals, humans can develop local adaptations to particular environments, reflected in perceptual frameworks, behavioural patterns, and genetical characteristics. However, scientific evidence for local adaptation in humans remains relatively limited and underreported in the scientific literature. This study investigates human adaptation to an active volcanic environment, where generations persist despite catastrophic risk. Applying this biological framework, the research examines adaptation at the cognitive, behavioural, and genetic levels on the slopes of Mount Semeru (East Java, Indonesia).&#13;
Through a large scale lab-in-the-field experiment within this natural laboratory of recurrent volcanic risk, and by exploiting an unexpected major eruption that occurred during data collection, we compared communities in the high-risk zone with those in relatively safer areas. Our findings show that chronic exposure to volcanic hazard shapes a unique adaptive perception. Residents in the high-risk zones perceive tangible and intangible benefits that offset objective threat. This context-specific rationale forms a foundational adaptive phenotype that overrides baseline demographic differences such as gender. This study also finds that long-term exposure shapes a stable behavioural phenotype of increased individual risk aversion, while socio-cultural norms such gotong-royong (mutual assistance) maintain stable prosocial tendencies. The 2021 Semeru eruption acted as a temporary catalyst, triggering a surge in solidarity without altering this underlying caution. This pattern demonstrates a dual adaptive strategy, where persistent hazard shapes personal caution, while sudden catastrophe triggers collective solidarity.&#13;
Genetic analysis of the DRD4 gene, associated with novelty seeking, reveals a more complex picture. Although allele frequency differences were observed between zones, this genetic variation was not directly linked to financial risk taking in experiments. Instead, factor such as gender, age, number of children, and temporal context relative to the eruption showed significant associations. This suggest that the well-documented risk aversion among high-risk zone residents is not driven by simple genetic determinism.&#13;
Overall, our study demonstrates that human persistence in extreme environments is built through integrated multi-level adaptation. A uniquely calibrated perception of the landscape enables habitation, which translates into a chronic personal caution phenotype, while deeply rooted cultural norms like gotong royong ensure stable prosociality and enable a strong, flexible response to acute crises. Together, these cognitive, behavioural, and cultural layers, interacting with a complex genetic basis, constitute a comprehensive model of human resilience on an active volcano.
</description>
<dc:date>2026-01-01T00:00:00Z</dc:date>
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