The dactyl plunger of Alpheus sp. was found to be a layered composite, with mineral-rich outer and inner layers and a chitin-rich middle layer of high porosity. The chitin-rich middle layer is itself composed of several porous chitin laminae. Modelling heat conduction through the plunger cross-section revealed that the chitin-rich layer is able to insulate heat and retard its progress through the material. Heat accumulates in the plunger after a series of successive snaps and as such, its thermally resistant design can be considered most useful under the conditions of successive snapping. The plunger has a concurrent mechanical damage-tolerant design with biogenic mineral layers, viscous (chitin-mineral) interfaces, energy-dissipating porous chitin, and sidewalls composed of ordered, layered aragonite. The snapping shrimp plunger has a design that may protect it and internal soft tissues from thermomechanical damage during plunger-socket compression prior to cavitation bubble release.

BackgroundNucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of highly active antiretroviral therapy combination regimens for HIV infection. Unfortunately, NRTIs have been noticeably associated with many adverse effects related to mitochondrial toxicity leading to mitochondrial deoxyribonucleic acid (mtDNA) depletion. However, similar mitochondrial dysfunction has recently been found even in antiretroviral therapy-naïve patients, suggesting HIV itself could contribute to this abnormality. In this study, we determine whether mtDNA depletion was present in either antiretroviral therapy-naïve or NRTI-treated patients at Sanjiwani Hospital, Bali, Indonesia.Patients and methodsA cross-sectional study was conducted from the peripheral blood mononuclear cells of HIV patients. Specifically, the relative content of mtDNA (mtRNR1 gene) to nuclear DNA (ASPOLG gene) was determined by real-time polymerase chain reaction. Data were analyzed with SPSS 16.0 software and GraphPad Prism 7.02.ResultsA total of 84 samples (67 on NRTIs and 17 HIV-naïve) were suitable for analysis. We identified 21.4% of the samples (18/84) with mtDNA:nDNA ratio <1. Although it was not significant (P=0.121), the median mtDNA:nDNA ratio of HIV-naïve group was slightly higher (median 1.8; interquartile range [IQR]: 1.1–2.1) than NRTI-treated patients (median 1.5; IQR: 1.3–2.85). Tenofovir-based NRTI was more frequently used (73.13%) than zidovudine-based NRTI (26.86%). The period for which NRTI was used probably contributed to the ratio of mtDNA:nDNA. The median ratio of mtDNA:nDNA zidovudine-treated patients was slightly lower (median 1.2; IQR: 1.08–1.98) when compared to tenofovir-based NRTI (median 1.6; IQR: 1.05–2.10), with the median period of former treatment being significantly longer (P<0.001). Although these data overall indicate that NRTI treatment had no effect on mtDNA:nDNA ratios, patients who undergo more than 12 months of NRTIs treatment show a decrease in the ratio; however, further study is required.ConclusionAlmost one-fourth of the samples showed a lower mtDNA:nDNA ratio. The decreasing of the ratio mtDNA:nDNA was most likely present after 12 months of NRTI treatment.

Metformin is the most common drug prescribed for patient with type 2 diabetes mellitus (T2DM). Although it is widely used as first line therapy for T2DM, there were huge variations in its clinical efficacy among population. It was postulated that genetic polymorphisms of metformin transporter, especially organic cation transporter 1 (OCT1) encoded by SLC22A1 gene, have a considerable effect on respon of metformin therapy. However, data for this polymorphism in Balinese population was not well established. The aim of this study was to identify genetic variation in OCT1, especially rs628031, rs122083571, and rs623442, in Balinese diabetic patients. It was a descriptive study to explore genetic variation in OCT1 encoded by SLC22A1 gene. A total of 133 diabetic patients were recruited from Departement of Internal Medicine at Sanjiwani Hospital Gianyar and Tabanan Hospital, Bali. DNA was extracted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to assess the polymorphism rs628031. While, polymorphism rs122083571 and rs623442 were assessed by direct sequencing. The minor allele frequency (MAF) for polymorphism rs628031 in this population was 0.59 with genotype frequency of AA, AG, and GG accounted for 16.5%; 48.9%, and 34.6% respectively. Minor allele frequency for polymorphism rs623442 was 0.20 with genotype frequency of CC, CA, and AA 5.4%; 29.0%; and 65.6% respectively. Polymorphism rs122083571 was not found in this population (100% genotype CC). Genetic polymorphism of OCT1 rs628031 in this population was occurred in relatively high frequency, while polymorphism OCT1 rs623442 was occurred only in one fifth of studied population. Further studies are needed to address the effect of this polymorphism to therapeutic respons of metformin in Balinese population.