Eliminasi Gangguan Matriks Dalam Analisis Merkuri Hg Sebagai Senyawa Kompleks Thio Michler\u27s Keton Secara Spektrofotometri

. A research of analysis method for determination of mercury through formation of complex with 4,4\u27-bis(dimethylamino)thiobenzophenone TMK has been conducted. The green blue complex compound can be detected with spectrophoto-meter in conditions: lmax 574 nm, buffer acetate pH 3, concentration of TMK 0,0002 M, and the absorbance of complex remains stable for 4–10 minutes. The formula of reagents volume for: Hg(II): buffer acetate pH 3: TMK 0,002 M : de-ionized water is 1:1:1:7. This method is valid, with parameters such as linearity 0.05–2.00 mg/L, limit of detection 0.008 mg/L, and recovery in the range 98%-102%. Matrix interferences that are caused by Au(III), Ag(I), Pd(II), Cu(II), Co(II), and Fe(III) ions can be eliminated with solvent extraction and standard addition methods. Standard addition method is able to give data of trusty measurement result at a 5%, that is for synthesis sample as (0.053 ± 0.001) mg/L, river water (0.034 ± 0.004) mg/L, and for sediment (4.172 ± 0.050) mg/kg. From the result of this research, it can be concluded that solvent extraction and standard addition methods are able to eliminated matrix interferences in mercury analysis as Hg-TMK complex spectrophotometrically Key waords: mercury analysis method, Thio Michler\u27s ketone, elimination, matrix interference

Faktor-faktor Yang Mempengaruhi Efektifitas Penerapan Sistem Haccp

Industri pangan tidak hanya bertanggung jawab untuk memproduksi makanan yang aman tetapi juga dapat menunjukkan secara transparan bagaimana keamanan pangan telah direncanakan dan terjamin. Hal ini dapat dicapai melalui pengembangan Hazard Analysis of Critical Control Points (HACCP) sebagai bagian dari sistem jaminan keamanan pangan Perusahaan. Pada prakteknya pencapaian tujuan dan sasaran dari penerapan HACCP tidak selalu berhasil. Faktor-faktor yang menjadi hambatan dalam penerapan HACCP harus dapat terdefinisi dengan jelas dan dievaluasi dampaknya terhadap efektifitas penerapan HACCP. Tujuan penelitian ini adalah menentukan dan menganalisa faktor yang mempengaruhi penerapan sistem HACCP serta mengetahui langkah-langkah untuk mengatasi hambatan yang diakibatkan oleh faktor penghambat untuk mencapai efektifitas penerapan sistem HACCP. Penelitian ini mengambil kasus pada penerapan HACCP di PT. Tirta Investama plant Subang, Plant Mekarsari dan Plant Citeurep. Responden pada penelitian ini adalah manajer dan supervisor. Hasil penelitian ini diketahui atribut manusia dan atribut Perusahaan merupakan faktor yang mempengaruhi efektifitas penerapan sistem HACCP. Langkah penting yang perlu dilakukan Perusahaan untuk mengatasi hambatan tersebut adalah mengembangkan program training untuk karyawan di semua level secara berkelanjutan, memastikan pelaksanaan Good Manufacturing Practices/ Prerequisite Program berjalan dengan baik yaitu dengan melakukan audit secara berkala dan membangun metode komunikasi yang efektif

MicroRNAs and cancer metabolism reprogramming : the paradigm of metformin

Increasing evidence witnesses that cancer metabolism alterations represent a critical hallmark for many types of human tumors. There is a strong need to understand and dissect the molecular mechanisms underlying cancer metabolism to envisage specific biomarkers and underpin critical molecular components that might represent novel therapeutic targets. One challenge, that is the focus of this review, is the reprogramming of the altered metabolism of a cancer cell toward that of un-transformed cell. The anti-hyperglicemic agent, metformin has proven to be effective in reprogramming the metabolism of cancer cells even from those subpopulations endowed with cancer stem like features and very high chemoresistenace to conventional anticancer treatments. A functional interplay involving selective modulation of microRNAs (miRNAs) takes place along the anticancer metabolic effects exerted by metformin. The implications of this interplay will be also discussed in this review

Upaya Meningkatkan Pemahaman Mahasiswa Akan Konsep-konsep Kimia Dengan Penerapkan Paduan Metode Demonstrasi Dan Metode Kooperatif Lt

. Telah dilakukan penelitian tentang efektivitas penerapan metode demonstrasi-kooperatif LT dalam pembelajaran matakuliah Kimia Dasar pada topik stoikhiometri dan kesetimbangan kimia. Tujuan penelitian ini untuk menguji keefektifan paduan metode demonstrasi dan pendekatan pembelajaran kooperatif tipe LT dengan pembelajaran konvensional terhadap hasil belajar Kimia Dasar. Metode penelitian yang digunakan adalah eksperimen semu (quasi experiment) dengan menggunakan kelas kontrol (pembelajaran menggunakan metode konvensional) dan kelas eksperimen (menggunakan metode demonstrasi-kooperatif LT). Dari hasil penelitian ini diperoleh bahwa penerapan metode demontrasi-kooperatif tipe learning together (demonstrasi-kooperatif LT) dapat meningkatkan aktivitas yang ditunjukkan oleh terwujudnya persiapan belajar, partisipasi antar individu, partisipasi yang berkualitas, keseriusan, bekerja sama, saling ketergantungan positif, mengutamakan interaksi tatap muka/tidak individualistis, tanggungjawab individu, kemampuan memotivasi kelompok, kemampuan mengambil kesimpulan dari berbagai pendapat dalam kelompoknya. Secara kuantitatif nilai hasil belajar mahasiswa yang diajar dengan metode demonstrasi-kooperatif LT adalah sebesar 72,67 dan metode konvensional sebesar 61,19. Dari hasil uji statistik diperoleh bahwa t-hitung > t-tabel (a =0,05), sehingga Ho ditolak. Kesimpulan yang diperoleh dari penel;itian ini adalah terdapat perbedaan yang signifikan keefektifan antara metode konvensional dan metode demonstrasi-kooperatif tipe LT dalam meningkatkan kualitas dan hasil belajar Kimia Dasa

Metabolic syndrome and postmenopausal breast cancer in the ORDET cohort : a nested case-control study

Background and aims: The increase in breast cancer incidence over recent decades has been accompanied by an increase in the frequency of metabolic syndrome. Several studies suggest that breast cancer risk is associated with the components of metabolic syndrome (high serum glucose and triglycerides, low HDL-cholesterol, high blood pressure, and abdominal obesity), but no prospective study has investigated risk in relation to the presence of explicitly defined metabolic syndrome. We investigated associations between metabolic syndrome, its components, and breast cancer risk in a nested case-control study on postmenopausal women of the ORDET cohort. Methods and results: After a median follow-up of 13.5 years, 163 women developed breast cancer; metabolic syndrome was present in 29.8%. Four matched controls per case were selected by incidence density sampling, and rate ratios were estimated by conditional logistic regression. Metabolic syndrome (i.e. presence of three or more metabolic syndrome components) was significantly associated with breast cancer risk (rate ratio 1.58 [95% confidence interval 1.07-2.33]), with a significant risk increase for increasing number of components (P for trend 0.004). Among individual metabolic syndrome components, only low serum HDL-cholesterol and high triglycerides were significantly associated with increased risk. Conclusions: This prospective study indicates that metabolic syndrome is an important risk factor for breast cancer in postmenopausal women. Although serum HDL-cholesterol and triglycerides had the strongest association with breast cancer, all components may contribute to increased risk by multiple interacting mechanisms. Prevention or reversal of metabolic syndrome by life-style changes may be effective in preventing breast cancer in postmenopausal women

Graphene oxide integrated sensor for electrochemical monitoring ofmitomycin C–DNA interaction

WOS: 000302308600025PubMed ID: 22439135We present a graphene oxide (GO) integrated disposable electrochemical sensor for the enhanced detection of nucleic acids and the sensitive monitoring of the surface-confined interactions between the anticancer drug mitomycin C (MC) and DNA. Interfacial interactions between immobilized calf thymus double-stranded (dsDNA) and anticancer drug MC were investigated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Based on three repetitive voltammetric measurements of 120 mu g mL(-1) DNA immobilized on GO-modified electrodes, the RSD % (n = 3) was calculated as 10.47% and the detection limit (DL) for dsDNA was found to be 9.06 mu g mL(-1). EIS studies revealed that the binding of the drug MC to dsDNA leads to a gradual decrease of its negative charge. As a consequence of this interaction, the negative redox species were allowed to approach the electrode, and thus increase the charge transfer kinetics. On the other hand, DPV studies exploited the decrease of the guanine signal due to drug binding as the basis for specifically probing the biointeraction process between MC and dsDNA.Royal Society through Joint Project Scheme [1212R0168]; Turkish Academy of Sciences (TUBA)Turkish Academy of SciencesThis work was supported by the Royal Society through Joint Project Scheme (Project No. 1212R0168). A.E. acknowledges the Turkish Academy of Sciences (TUBA) as an Associate member for its partial support. Authors would like to thank Dr. M. McMullan for the assistance on the synthesis of graphene oxide

A novel approach to breast cancer prevention: reducing excessive ovarian androgen production in elderly women

Minimizing endogenous estrogen production and activity in women at high risk for breast cancer is a prominent approach to prevention of the disease. A number of clinical trials have shown that the administration of selective-estrogen receptor modulators or aromatase inhibitors significantly reduces the incidence of breast cancer in healthy women. Unfortunately, these drugs often produce adverse effects on the quality of life and are, therefore, poorly accepted by many women, even those who are at high risk for breast cancer. We propose a novel alternative approach to decreasing estrogen production: suppression of ovarian synthesis of the androgen precursors of estrogens by administration of long-acting gonadotropin-releasing hormone analogs to women with ovarian stromal hyperplasia. The specific target population would be elderly postmenopausal women, at increased risk of breast cancer, and with high blood levels of testosterone, marker of ovarian hyperandrogenemia, and recognized factor of risk for breast cancer. Testosterone levels are measured at baseline to identify women at risk and during the follow-up to evaluate the effectiveness of therapy. The postmenopausal ovary is an important source of excessive androgen production which originates from the ovarian interstitial cell hyperplasia frequently present in breast cancer patients. We propose to counter the source of androgen excess in women with ovarian stromal hyperplasia, thus reducing the substrate for estrogen formation without completely inhibiting estrogen synthesis. Available evidence indicates that gonadotropin-releasing hormone analogs can be safely used for breast cancer prevention in postmenopausal women

Novel biomarker SARIFA in colorectal cancer: highly prognostic, not genetically driven and histologic indicator of a distinct tumor biology

SARIFA (Stroma AReactive Invasion Front Areas) has recently emerged as a promising histopathological biomarker for colon and gastric cancer. To elucidate the underlying tumor biology, we assessed SARIFA-status in tissue specimens from The-Cancer-Genome-Atlas (TCGA) cohorts COAD (colonic adenocarcinoma) and READ (rectal adenocarcinoma). For the final analysis, 207 CRC patients could be included, consisting of 69 SARIFA-positive and 138 SARIFA-negative cases. In this external validation cohort, H&E-based SARIFA-positivity was strongly correlated with unfavorable overall, disease-specific, and progression-free survival, partly outperforming conventional prognostic factors. SARIFA-positivity was not associated with known high-risk genetic profiles, such as BRAF V600E mutations or microsatellite-stable status. Transcriptionally, SARIFA-positive CRCs exhibited an overlap with CRC consensus molecular subtypes CMS1 and CMS4, along with distinct differential gene expression patterns, linked to lipid metabolism and increased stromal cell infiltration scores (SIIS). Gene-expression-based drug sensitivity prediction revealed a differential treatment response in SARIFA-positive CRCs. In conclusion, SARIFA represents the H&E-based counterpart of an aggressive tumor biology, demonstrating a partial overlap with CMS1/4 and also adding a further biological layer related to lipid metabolism. Our findings underscore SARIFA-status as an ideal biomarker for refined patient stratification and novel drug developments, particularly given its cost-effective assessment based on routinely available H&E slides

Agave negatively regulates YAP and TAZ transcriptionally and post-translationally in osteosarcoma cell lines

Osteosarcoma (OS) is the most aggressive type of primary solid tumor that develops in bone. Whilst conventional chemotherapy can improve survival rates, the outcome for patients with metastatic or recurrent OS remains poor, so novel treatment agents and strategies are required. Research into new anticancer therapies has paved the way for the utilisation of natural compounds as they are typically less expensive and less toxic compared to conventional chemotherapeutics. Previously published works indicate that Agave exhibits anticancer properties, however potential molecular mechanisms remain poorly understood. In the present study, we investigate the anticancer effects of Agave leaf extract in OS cells suggesting that Agave inhibits cell viability, colony formation, and cell migration, and can induce apoptosis in OS cell lines. Moreover, Agave sensitizes OS cells to cisplatin (CDDP) and radiation, to overcome chemo- and radio-resistance. We demonstrate that Agave extract induces a marked decrease of Yes Associated Protein (YAP) and Tafazzin (TAZ) mRNA and protein expression upon treatment. We propose an initial mechanism of action in which Agave induces YAP/TAZ protein degradation, followed by a secondary event whereby Agave inhibits YAP/TAZ transcription, effectively deregulating the Nuclear Factor kappa B (NF-\u3baB) p65:p50 heterodimers responsible for transcriptional induction of YAP and TAZ