13 research outputs found
Pengembangan Modul Berbasis Bounded Inquiry Laboratory (Lab) Untuk Meningkatkan Literasi Sains Dimensi Proses Pada Materi Sistem Pencernaan Kelas XI
Penelitian bertujuan untuk: 1) Mengetahui karakteristik modul berbasis bounded inquiry laboratory (lab) untuk meningkatkan literasi sains dimensi proses; 2) Menguji kelayakan modul berbasis bounded inquiry laboratory (lab) untuk meningkatkan literasi sains dimensi proses; 3) Menguji keefektivan penggunaan modul berbasis bounded inquiry laboratory (lab) untuk meningkatkan literasi sains dimensi proses pada materi Sistem Pencernaan kelas XI. Penelitian ini menggunakan metode Research and Development (R & D) mengacu pada model Borg and Gall (1983) yang dimodifikasi. Instrumen yang digunakan adalah lembar analisis, lembar observasi, angket, lembar validasi, wawancara, dan tes. Data penelitian dianalisis dengan metode deskriptif kualitatif dan literasi sains dimensi proses dianalisis dengan N-gain ternormalisasi untuk mengetahui keefektivan modul berbasis bounded inquiry laboratory (lab), dan uji Wilcoxon untuk mengetahui literasi sains dimensi proses. Hasil penelitian dan pengembangan menunjukkan bahwa: 1) Modul berbasis bounded inquiry laboratory (lab) untuk meningkatkan literasi sains dimensi proses pada materi Sistem Pencernaan dikembangkan sesuai dengan tahapan bounded inquiry laboratory (lab) (observasi, manipulasi, generalisasi, verifikasi, aplikasi) dan pendekatan saintifik; 2) Hasil pengembangan modul berbasis bounded inquiry laboratory (lab) layak untuk diterapkan pada materi Sistem Pencernaan. Kelayakan modul berbasis bounded inquiry laboratory (lab) pada materi Sistem Pencernaan berdasarkan validasi ahli memperoleh kategori “sangat baik” dengan persentase 98,21%, validasi praktisi memperoleh kategori “sangat baik” dengan persentase 99,22%, dan responden uji coba skala kecil memperoleh kategori “baik” dengan persentase 77,34%, sehingga layak digunakan kelas XI; 3) Modul berbasis bounded inquiry laboratory (lab) pada materi Sistem Pencernaan efektif untuk meningkatkan literasi sains dimensi proses yang ditunjukkan dengan hasil uji Wilcoxon yaitu diperoleh probabilitas (p) sebesar 0,000 (p < 0,05), H0 ditolak, sehingga ada perbedaan literasi sains dimensi proses sebelum dan setelah menggunakan modul bounded inquiry laboratory (lab) pada materi sistem pencernaan. Berdasarkan hasil penelitian dapat disimpulkan bahwa karakteristik modul berbasis bounded inquiry laboratory (lab) sesuai tahapan bounded inquiry laboratory (lab) (observasi, manipulasi, generalisasi, verifikasi, aplikasi) dan pendekatan saintifik; layak dan efektif untuk meningkatkan literasi sains dimensi proses pada materi Sistem Pencernaan kelas XI
In vivo Diffusion MRI Detects Early Changes in Spinal Cord Axonal Pathology in a Mouse Model of Amyotrophic Lateral Sclerosis
Diffusion magnetic resonance imaging (MRI) exhibits contrast that identifies macro- and microstructural changes in neurodegenerative diseases. Previous studies have shown that MR diffusion tensor imaging (DTI) can observe changes in spinal cord white matter in animals and humans affected with symptomatic amyotrophic lateral sclerosis (ALS). The goal of this preclinical work was to investigate the sensitivity of DTI for the detection of signs of tissue damage before symptoms appear. High-field MRI data were acquired using a 9.4-T animal scanner to examine the spinal cord of an ALS mouse model at pre- and post-symptomatic stages (days 80 and 120, respectively). The MRI results were validated using yellow fluorescent protein (YFP) via optical microscopy of spinal cord tissue slices collected from the YFP,G93A-SOD1 mouse strain. DTI maps of diffusion-weighted imaging (DWI) signal intensity, mean diffusivity (MD), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) were computed for axial slices of the lumbar region of the spinal cord. Significant changes were observed in FA (6.7% decrease, p < 0.01), AD (19.5% decrease, p < 0.01) and RD (16.1% increase, p < 0.001) at postnatal day 80 (P80). These differences were correlated with changes in axonal fluorescence intensity and membrane cellular markers. This study demonstrates the value of DTI as a potential tool to detect the underlying pathological progression associated with ALS, and may accelerate the discovery of therapeutic strategies for patients with this disease
Joining mechanism evolution of fusion welded TC4 titanium alloy/304 stainless steel dissimilar joint by GTAW
Gas tungsten arc welding with a pure Cu filler wire was carried out to join the TC4 titanium alloy and 304 stainless steel. Filling pure Cu filler wire assisted with regulating welding current could effectively restrain the concentrated generation of Ti–Fe brittle intermetallic compounds. Three joining modes exist in the fusion welding titanium alloy and stainless steel. In the partial fusion welding mode, the TiCu phase decreased and the fine granular τ2 phase formed in the Ti/Cu interfacial zone, simultaneously, the molten zone consisted of a Cu solid solution and α-(Fe, Cr) phase formed at the Cu/Fe interface, resulting in mechanical interlocking effect and consequent high tensile strength of 363 MPa. Increasing the welding current would lead to the alloying of TixCuy phases, and then enhance the Ti/Cu interface.</p
ARRDC3 regulates the targeted therapy sensitivity of clear cell renal cell carcinoma by promoting AXL degradation
AXL plays crucial roles in the tumorigenesis, progression, and drug resistance of neoplasms; however, the mechanisms associated with AXL overexpression in tumors remain largely unknown. In this study, to investigate these molecular mechanisms, wildtype and mutant proteins of arrestin domain-containing protein 3 (ARRDC3) and AXL were expressed, and co-immunoprecipitation analyses were performed. ARRDC3-deficient cells generated using the CRISPR-Cas9 system were treated with different concentrations of the tyrosine kinase inhibitor sunitinib and subjected to cell biological, molecular, and pharmacological experiments. Furthermore, immunohistochemistry was used to analyze the correlation between ARRDC3 and AXL protein expressions in renal cancer tissue specimens. The experimental results demonstrated that ARRDC3 interacts with AXL to promote AXL ubiquitination and degradation, followed by the negative regulation of downstream signaling mechanisms, including the phosphorylation of protein kinase B and extracellular signal-regulated kinase. Notably, ARRDC3 deficiency decreased the sunitinib sensitivity of clear cell renal cell carcinoma (ccRCC) cells in a manner dependent on the regulation of AXL stability. Overall, our results suggest that ARRDC3 is a negative regulator of AXL and can serve as a novel predictor of sunitinib therapeutic response in patients with ccRCC.</p
Anomalous NMR Relaxation in Cartilage Matrix Components and Native Cartilage: Fractional-Order Models
We present a fractional-order extension of the Bloch equations to describe anomalous NMR relaxation phenomena (T(1) and T(2)). The model has solutions in the form of Mittag-Leffler and stretched exponential functions that generalize conventional exponential relaxation. Such functions have been shown by others to be useful for describing dielectric and viscoelastic relaxation in complex, heterogeneous materials. Here, we apply these fractional-order T(1) and T(2) relaxation models to experiments performed at 9.4 and 11.7 Tesla on type I collagen gels, chondroitin sulfate mixtures, and to bovine nasal cartilage (BNC), a largely isotropic and homogeneous form of cartilage. The results show that the fractional-order analysis captures important features of NMR relaxation that are typically described by multi-exponential decay models. We find that the T(2) relaxation of BNC can be described in a unique way by a single fractional-order parameter (α), in contrast to the lack of uniqueness of multi-exponential fits in the realistic setting of a finite signal-to-noise ratio. No anomalous behavior of T(1) was observed in BNC. In the single-component gels, for T(2) measurements, increasing the concentration of the largest components of cartilage matrix, collagen and chondroitin sulfate, results in a decrease in α, reflecting a more restricted aqueous environment. The quality of the curve fits obtained using Mittag-Leffler and stretched exponential functions are in some cases superior to those obtained using mono- and bi-exponential models. In both gels and BNC, α appears to account for micro-structural complexity in the setting of an altered distribution of relaxation times. This work suggests the utility of fractional-order models to describe T(2) NMR relaxation processes in biological tissues
Microstructure and mechanical properties of SiCp/AZ91 composite processed with extrusion and EPT
By hot extrusion at 250°C and electrical pulse treatment (EPT) of 40 μs duration and 10 min processing time, a homogeneous matrix microstructure with an average grain size of 0.91 μm and abundant Mg17Al12 phase was obtained in SiCp/AZ91 magnesium matrix composite. Moreover, SiCp were helpful to promote the accumulation of crystal defects and the precipitation of Mg17Al12 phase. After extrusion at 250°C, the yield strength (YS) and ultimate tensile strength (UTS) of the composite reached 480 and 556 MPa, respectively. With the increase of the duration and the processing time, the YS and UTS of SiCp/AZ91 composite were reduced due to the softening effect of static recrystallisation but its tensile elongation to failure (TEF) was improved slightly
Detection of G‑Quadruplex Structures Formed by G‑Rich Sequences from Rice Genome and Transcriptome Using Combined Probes
Putative
G-quadruplex (G4) forming sequences (PQS) are highly prevalent
in the genome and transcriptome of various organisms and are considered
as potential regulation elements in many biological processes by forming
G4 structures. The formation of G4 structures highly depends on the
sequences and the environment. In most cases, it is difficult to predict
G4 formation by PQS, especially PQS containing G2 tracts. Therefore,
the experimental identification of G4 formation is essential in the
study of G4-related biological functions. Herein, we report a rapid
and simple method for the detection of G4 structures by using a pair
of complementary reporters, hemin and BMSP. This method was applied
to detect G4 structures formed by PQS (DNA and RNA) searched in the
genome and transcriptome of Oryza sativa. Unlike most of the reported G4 probes that only recognize part
of G4 structures, the proposed method based on combined probes positively
responded to almost all G4 conformations, including parallel, antiparallel,
and mixed/hybrid G4, but did not respond to non-G4 sequences. This
method shows potential for high-throughput identification of G4 structures
in genome and transcriptome. Furthermore, BMSP was observed to drive
some PQS to form more stable G4 structures or induce the G4 formation
of some PQS that cannot form G4 in normal physiological conditions,
which may provide a powerful molecular tool for gene regulation
Prioritizing Disease Candidate Proteins in Cardiomyopathy-Specific Protein-Protein Interaction Networks Based on “Guilt by Association” Analysis
<div><p>The cardiomyopathies are a group of heart muscle diseases which can be inherited (familial). Identifying potential disease-related proteins is important to understand mechanisms of cardiomyopathies. Experimental identification of cardiomyophthies is costly and labour-intensive. In contrast, bioinformatics approach has a competitive advantage over experimental method. Based on “guilt by association” analysis, we prioritized candidate proteins involving in human cardiomyopathies. We first built weighted human cardiomyopathy-specific protein-protein interaction networks for three subtypes of cardiomyopathies using the known disease proteins from Online Mendelian Inheritance in Man as seeds. We then developed a method in prioritizing disease candidate proteins to rank candidate proteins in the network based on “guilt by association” analysis. It was found that most candidate proteins with high scores shared disease-related pathways with disease seed proteins. These top ranked candidate proteins were related with the corresponding disease subtypes, and were potential disease-related proteins. Cross-validation and comparison with other methods indicated that our approach could be used for the identification of potentially novel disease proteins, which may provide insights into cardiomyopathy-related mechanisms in a more comprehensive and integrated way.</p></div
DCM pathway.
<p>DCM seed proteins are colored in cyan. Red nodes are proteins which were verified to be DCM-related proteins, and yellow nodes represent proteins which are potential DCM-related proteins.</p
Official symbols of seed genes of DCM, HCM and ARVC.
*<p>Accession number of the corresponding protein.</p