Preliminary Investigation of the GCL’s Boiling toward An Upward Water Flow

The performance of GCL as liquid barrier depends on its hydraulic performance. During its application, the GCL may encounter high water level and opposite water flow from ground water that can cause the failure of the GCL in maintaining its water tight. In this experiment, the high water pressure coming from above pushed the GCL to be thinner in some part and trigger the bentonite powder to escape from its carrier. However, the GCL did not lose its capacity to retain the water flow. Meanwhile, the opposite direction of water pressure applied afterward had a significant effect to the GCL performance after three days. The hydraulic performance of the GCL dropped significantly alongside with some physical changes on the GCL’s cover. The boiling of bentonite was built up during the failure of the GCL

Study on the GCL’s Response to Hydraulic Uplift

Most of landfill sites in developed countries employ GCL as bottom liners to replace compacted clay liner. However, various water level and direction might be faced by GCL during its operation. These conditions can make the GLC to deform and decrease its hydraulic capability. In this experiment, the GCL was tested with two direction of water flow to see whether any deformation that causes the GCL to lose its hydraulic performance. The results showed that the hydraulic performance of the GCL was constant while facing a water flow coming from above even some area started to be slightly thinner than others. In contrast, the GCL started to uplift, curved and lost its hydraulic performance when thewater pressure coming from underneath. The bentonite particles also moved aside from higher hydraulic pressure zone into lower pressure area creating diverse thickness

Hipertensi sebagai salah satu faktor risiko terjadinya degenerasi makula senilis

Hypertension as one of the risk factors for age-related macular degeneration Background: Age-related macular degeneration (ARMD) is one of the causes of loss of central vision in older people. While age is the undisputed, the most important risk factors such as genetic, race, sex, sunlight exposure, diet, vitamin, smoking, cardiovascular disease, hypercholesterolemia, and hypertension have been incriminated to be associated with the development of ARMD. The study of ARMD is very rare in Indonesia. Objectives: To investigate the possible association of presumed hypertension, and other risk factors in patients with age-related macular degeneration. Methode: A case-control study of 120 subjects, 60 cases with ARMD and 60 cases of normal control in Dr. Sardjito General Hospital and Dr. YAP. Eye Hospital, Yogyakarta. ARMD and normal control were compared. Interview, eye examination, blood pressure, and blood sample were performed. Results: Hypertension was observed in 38 (76%) of 60 patients with age-related macular degeneration. Of 60 normal control patients, only 12 (24%) had hypertension. Statistical analysis result showed that hypertension was one of the risk factors for the development of age-related macular degeneration OR: 6,909 (3,037-15,720). But hypertension was not a predictor for the development of age-related macular degeneration (regression coefficient = 0,0000). Conclusion: Besides other risk factors, hypertension is one of the risk factors for the development of age-related macular degeneration. Key words: age-related macular degeneration - central vision - older people - risk factors - hypertensio

Bistability in Apoptosis by Receptor Clustering

Apoptosis is a highly regulated cell death mechanism involved in many physiological processes. A key component of extrinsically activated apoptosis is the death receptor Fas, which, on binding to its cognate ligand FasL, oligomerize to form the death-inducing signaling complex. Motivated by recent experimental data, we propose a mathematical model of death ligand-receptor dynamics where FasL acts as a clustering agent for Fas, which form locally stable signaling platforms through proximity-induced receptor interactions. Significantly, the model exhibits hysteresis, providing an upstream mechanism for bistability and robustness. At low receptor concentrations, the bistability is contingent on the trimerism of FasL. Moreover, irreversible bistability, representing a committed cell death decision, emerges at high concentrations, which may be achieved through receptor pre-association or localization onto membrane lipid rafts. Thus, our model provides a novel theory for these observed biological phenomena within the unified context of bistability. Importantly, as Fas interactions initiate the extrinsic apoptotic pathway, our model also suggests a mechanism by which cells may function as bistable life/death switches independently of any such dynamics in their downstream components. Our results highlight the role of death receptors in deciding cell fate and add to the signal processing capabilities attributed to receptor clustering.Comment: Accepted by PLoS Comput Bio

Photoactive nano-confined Pt in titania nanotubes (Pt-TiNT) via microwave-assisted flow synthesis

Pt-TiNT with PtO nanoparticles dispersed within the lumen and interlayer spaces of titania nanotubes (TiNT) were prepared by a new process involving titanate nanosheets (TiNS) synthesis in an optimized microwave-assisted flow reactor, followed by ion-exchange with a Pt precursor, before triggering the titanate layer rolling to trap the Pt precursor clusters inside the titania nanotubes, followed by a thermal treatment. TEM, XRD, and Raman analyses confirm the total conversion of TiO2 into TiNS in 15 min at 120 °C and 4 bar, and the TiNS transformation into 181 nm-long TiNT with 10 and 6 nm outer and inner diameter, respectively. The 2% Pt-TiNT comprises 0.7 nm PtO clusters (according to XPS), causing slight distortions of the interlayer spaces, while a few larger 2–3 nm Pt clusters reside within the lumen. As a result, Pt-TiNT is 14-fold more active than TiNT for visible light (400–780 nm) photocatalytic oxidation of diclofenac under 2136 μW·cm−2 irradiation, and>1000-fold better than the uncatalyzed photoconversion reaction under 100 mW·cm−2 artificial solar lighting. In addition, nano-confinement of PtO clusters narrowed the bandgap of the TiNT, which, combined with its excellent absorptivity to harvest light, allowed a broader spectral range of photon energies to activate the photocatalyst.11 página

Potensi Sampah Combustible pada Zona Aktif 1 TPA Jatibarang Semarang sebagai Bahan Baku RDF (Refuse Derived Fuel)

Banyaknya produksi sampah di Semarang menyebabkan timbulan sampah di TPA Jatibarang semakin meningkat. Untuk mengurangi timbulan sampah, perlu adanya energi alternatif. Oleh karena itu, produksi refuse derived fuel (RDF) dapat menjadi salah satu solusi positif dalam penyelesaian masalah ini. Pemanfaatan energi dari limbah dikenal sebagai Waste-to-Energy (WTE). Pemanfaatan limbah menjadi energi sangat berhubungan dengan nilai kalor. Pada kajian ini, sampah combustible dari zona aktif 1 TPA Jatibarang akan dihitung nilai kalor tingginya dengan bom kalorimeter. Sampah diambil pada kedalaman 0-1 m, 1-2 m, dan 2-3 m di bawah permukaan timbulan sampah. Nilai kalor yang dihasilkan sampel tersebut sebesar 6,07 kkal/ton pada kedalaman 0-1 m, 5,56 kkal/ton pada kedalaman 1-2 m dan 5,55 kkal/ton pada kedalaman 2-3 m. Hal ini menunjukkan bahwa semakin tinggi kedalaman maka semakin tinggi pula nilai kalornya, sehingga sampah zona aktif 1 TPA Jatibarang memiliki potensi yang tinggi untuk diolah menjadi RDF

Photoactive nano-confined Pt in titania nanotubes (Pt-TiNT) via microwave-assisted flow synthesis

Pt-TiNT with PtO nanoparticles dispersed within the lumen and interlayer spaces of titania nanotubes (TiNT) were prepared by a new process involving titanate nanosheets (TiNS) synthesis in an optimized microwave-assisted flow reactor, followed by ion-exchange with a Pt precursor, before triggering the titanate layer rolling to trap the Pt precursor clusters inside the titania nanotubes, followed by a thermal treatment. TEM, XRD, and Raman analyses confirm the total conversion of TiO2 into TiNS in 15 min at 120 °C and 4 bar, and the TiNS transformation into 181 nm-long TiNT with 10 and 6 nm outer and inner diameter, respectively. The 2% Pt-TiNT comprises 0.7 nm PtO clusters (according to XPS), causing slight distortions of the interlayer spaces, while a few larger 2–3 nm Pt clusters reside within the lumen. As a result, Pt-TiNT is 14-fold more active than TiNT for visible light (400–780 nm) photocatalytic oxidation of diclofenac under 2136 μW·cm−2 irradiation, and>1000-fold better than the uncatalyzed photoconversion reaction under 100 mW·cm−2 artificial solar lighting. In addition, nano-confinement of PtO clusters narrowed the bandgap of the TiNT, which, combined with its excellent absorptivity to harvest light, allowed a broader spectral range of photon energies to activate the photocatalyst. © 2023 Elsevier B.V.This work is supported by the Horizon 2020 BIORIMA project and the Hong Kong Research Grant Council E-HKUST601/17 and in part by the Project of Hetao Shenzhen-Hong Kong University of Science and Technology Innovation Cooperation Zone (HZQB-KCZYB-2020083). Dr. Y.J. Luo stay at the Instituto de Cat´alisis y Petroleoquímica is supported by the HKUST Overseas Research Award. Finally, the authors acknowledge the support of the Central Facilities of the Hong Kong University of Science and Technology including the Material Characterization and Preparation Facility (MCPF) and the Environmental Central Facility (ENVF).Supplementary data to this article can be found online at https://doi. org/10.1016/j.cej.2023.143254Peer reviewe

Micro-Environmental Mechanical Stress Controls Tumor Spheroid Size and Morphology by Suppressing Proliferation and Inducing Apoptosis in Cancer Cells

Compressive mechanical stress produced during growth in a confining matrix limits the size of tumor spheroids, but little is known about the dynamics of stress accumulation, how the stress affects cancer cell phenotype, or the molecular pathways involved.We co-embedded single cancer cells with fluorescent micro-beads in agarose gels and, using confocal microscopy, recorded the 3D distribution of micro-beads surrounding growing spheroids. The change in micro-bead density was then converted to strain in the gel, from which we estimated the spatial distribution of compressive stress around the spheroids. We found a strong correlation between the peri-spheroid solid stress distribution and spheroid shape, a result of the suppression of cell proliferation and induction of apoptotic cell death in regions of high mechanical stress. By compressing spheroids consisting of cancer cells overexpressing anti-apoptotic genes, we demonstrate that mechanical stress-induced apoptosis occurs via the mitochondrial pathway.Our results provide detailed, quantitative insight into the role of micro-environmental mechanical stress in tumor spheroid growth dynamics, and suggest how tumors grow in confined locations where the level of solid stress becomes high. An important implication is that apoptosis via the mitochondrial pathway, induced by compressive stress, may be involved in tumor dormancy, in which tumor growth is held in check by a balance of apoptosis and proliferation

SMAC is expressed de novo in a subset of cervical cancer tumors

BACKGROUND: Smac/Diablo is a recently identified protein that is released from mitochondria after apoptotic stimuli. It binds IAPs, allowing caspase activation and cell death. In view of its activity it might participate in carcinogenesis. In the present study, we analyzed Smac expression in a panel of cervical cancer patients. METHODS: We performed semi quantitative RT-PCR on 41 cervical tumor and 6 normal tissue samples. The study included 8 stage I cases; 16 stage II; 17 stage III; and a control group of 6 samples of normal cervical squamous epithelial tissue. RESULTS: Smac mRNA expression was below the detection limit in the normal cervical tissue samples. In contrast, 13 (31.7%) of the 41 cervical cancer biopsies showed detectable levels of this transcript. The samples expressing Smac were distributed equally among the stages (5 in stage I, 4 in stage II and 4 in stage III) with similar expression levels. We found no correlation between the presence of Smac mRNA and histology, menopause, WHO stage or disease status. CONCLUSIONS: Smac is expressed de novo in a subset of cervical cancer patients, reflecting a possible heterogeneity in the pathways leading to cervical cancer. There was no correlation with any clinical variable