bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of intestinal parasites on microbiota and cobalamin gene sequences: a pilot study
Authors: Mejia Rojelio , Damania Ashish , Jeun Rebecca , Bryan Patricia E. , Vargas Paola , Juarez Marisa , Cajal Pamela S. , Nasser Julio , Krolewiecki Alejandro , Lefoulon Emilie , Long Courtney , Drake Evan , Cimino Rubén O. , Slatko Barton
Published: April 2020

Background

Approximately 30% of children worldwide are infected with gastrointestinal parasites. Depending on the species, parasites can disrupt intestinal bacterial microbiota affecting essential vitamin biosynthesis.

Methods

Stool samples were collected from 37 asymptomatic children from a previous cross-sectional Argentinian study. A multi-parallel real-time quantitative PCR was implemented for Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, Cryptosporidium spp., Entamoeba histolytica and Giardia duodenalis. In addition, whole-genome sequencing analysis was conducted for bacterial microbiota on all samples and analyzed using Livermore Metagenomic Analysis Toolkit and DIAMOND software. Separate analyses were carried out for uninfected, Giardia-only, Giardia + helminth co-infections, and helminth-only groups.

Results

For Giardia-only infected children compared to uninfected children, DNA sequencing data showed a decrease in microbiota biodiversity that correlated with increasing Giardia burden and was statistically significant using Shannonʼs alpha diversity (Giardia-only > 1 fg/µl 2.346; non-infected group 3.253, P = 0.0317). An increase in diversity was observed for helminth-only infections with a decrease in diversity for Giardia + helminth co-infections (P = 0.00178). In Giardia-only infections, microbiome taxonomy changed from Firmicutes towards increasing proportions of Prevotella, with the degree of change related to the intensity of infection compared to uninfected (P = 0.0317). The abundance of Prevotella bacteria was decreased in the helminths-only group but increased for Giardia + helminth co-infections (P = 0.0262). Metagenomic analysis determined cobalamin synthesis was decreased in the Giardia > 1 fg/µl group compared to both the Giardia < 1 fg/µl and the uninfected group (P = 0.0369). Giardia + helminth group also had a decrease in cobalamin CbiM genes from helminth-only infections (P = 0.000754).

Conclusion

The study results may provide evidence for an effect of parasitic infections enabling the permissive growth of anaerobic bacteria such as Prevotella, suggesting an altered capacity of vitamin B12 (cobalamin) biosynthesis and potential impact on growth and development in children .
Stability of the effect of silencing fibronectin type III domain-protein 1 (FN3D1) gene on Anopheles arabiensis reared under different breeding site conditions
Authors: Debalke Serkadis , Habtewold Tibebu , Christophides George K. , Duchateau Luc
Published: April 2020

Background

Malaria vector mosquitoes acquire midgut microbiota primarily from their habitat. The homeostasis of these microbial communities plays an essential role in the mosquito longevity, the most essential factor in the mosquito vectorial capacity. Our recent study revealed that silencing genes involved in regulation of the midgut homeostasis including FN3D1, FN3D3 and GPRGr9 reduced the survival of female adult Anopheles arabiensis mosquitoes. In the present study, we investigate the stability of the gene silencing efficiency of mosquitoes reared in three different breeding conditions representing distinct larval habitat types: town brick pits in Jimma, flood pools in the rural land of Asendabo and roadside pools in Wolkite.

Methods

First-instar larvae of An. arabiensis mosquitoes were reared separately using water collected from the three breeding sites. The resulting adult females were micro-injected with dsRNA targeting the FN3D1 gene (AARA003032) and their survival was monitored. Control mosquitoes were injected with dsRNA Lacz. In addition, the load of midgut microbiota of these mosquitoes was determined using flow cytometry.

Results

Survival of naïve adult female mosquitoes differed between the three sites. Mosquitoes reared using water collected from brick pits and flood pools survived longer than mosquitoes reared using water collected from roadside. However, the FN3D1 gene silencing effect on survival did not differ between the three sites.

Conclusions

The present study revealed that the efficacy of FN3D1 gene silencing is not affected by variation in the larval habitat. Thus, silencing this gene has potential for application throughout sub-Saharan Africa.
Transcriptome analysis and functional characterization of cerebral organoids in bipolar disorder
Authors: Kathuria Annie , Lopez-Lengowski Kara , Vater Magdalena , McPhie Donna , Cohen Bruce M. , Karmacharya Rakesh
Published: April 2020

Background

Reprogramming human induced pluripotent stem cells (iPSCs) from somatic cells and generating three-dimensional brain organoids from these iPSCs provide access to live human neuronal tissue with disease-specific genetic backgrounds.

Methods

Cerebral organoids were generated from iPSCs of eight bipolar disorder (BPI) patients and eight healthy control individuals. RNA-seq experiments were undertaken using RNA isolated from the cerebral organoids. Functional activity in the cerebral organoids was studied using microelectrode arrays.

Results

RNA-seq data comparing gene expression profiles in the cerebral organoids showed downregulation of pathways involved in cell adhesion, neurodevelopment, and synaptic biology in bipolar disorder along with upregulation of genes involved in immune signaling. The central hub in the network analysis was neurocan (NCAN), which is located in a locus with evidence for genome-wide significant association in BPI. Gene ontology analyses suggested deficits related to endoplasmic reticulum biology in BPI, which was supported by cellular characterization of ER–mitochondria interactions. Functional studies with microelectrode arrays revealed specific deficits in response to stimulation and depolarization in BPI cerebral organoids.

Conclusions

Our studies in cerebral organoids from bipolar disorder showed dysregulation in genes involved in cell adhesion, immune signaling, and endoplasmic reticulum biology; implicated a central role for the GWAS hit NCAN in the biology of BPI; and showed evidence of deficits in neurotransmission.
In patients with severe asthma with eosinophilia in reslizumab clinical trials, high peripheral blood eosinophil levels are associated with low FEV1 reversibility
Authors: Virchow J. Christian , Hickey Lisa , Du Evelyn , Garin Margaret
Published: April 2020

Background

A post hoc analysis of two randomized, placebo–controlled, Phase 3 trials of intravenous reslizumab, an anti-interleukin-5 (IL-5) biologic for severe eosinophilic asthma.

Methods

Relationships between baseline blood eosinophil levels (EOS), forced expiratory volume in 1 s (FEV1) reversibility to β2-agonists and treatment outcomes were assessed.

Results

Mean baseline FEV1 reversibility was numerically lower among patients with high (≥ 400 cells/µL) versus low baseline EOS. Reslizumab produced clinically significant improvement in FEV1, exacerbation rates and patient-reported outcomes after 52 weeks, including in patients with high EOS and low FEV1 reversibility (≤ 14%) to β2-agonists at baseline.

Conclusions

Clinical trial eligibility criteria stipulating minimum FEV1 reversibility to β2-agonists of ≥ 12% might exclude patients who would benefit from treatment with anti-IL-5 biologics.
Visual and quantitative evaluation of [18F]FES and [18F]FDHT PET in patients with metastatic breast cancer: an interobserver variability study
Authors: Mammatas Lemonitsa H. , Venema Clasina M. , Schröder Carolina P. , de Vet Henrica C. W. , van Kruchten Michel , Glaudemans Andor W. J. M. , Yaqub Maqsood M. , Verheul Henk M. W. , Boven Epie , van der Vegt Bert , de Vries Erik F. J. , de Vries Elisabeth G. E. , Hoekstra Otto S. , Hospers Geke A. P. , der Houven van Oordt C. Willemien Menke-van
Published: April 2020

Purpose

Correct identification of tumour receptor status is important for treatment decisions in breast cancer. [18F]FES PET and [18F]FDHT PET allow non-invasive assessment of the oestrogen (ER) and androgen receptor (AR) status of individual lesions within a patient. Despite standardised analysis techniques, interobserver variability can significantly affect the interpretation of PET results and thus clinical applicability. The purpose of this study was to determine visual and quantitative interobserver variability of [18F]FES PET and [18F]FDHT PET interpretation in patients with metastatic breast cancer.

Methods

In this prospective, two-centre study, patients with ER-positive metastatic breast cancer underwent both [18F]FES and [18F]FDHT PET/CT. In total, 120 lesions were identified in 10 patients with either conventional imaging (bone scan or lesions > 1 cm on high-resolution CT, n = 69) or only with [18F]FES and [18F]FDHT PET (n = 51). All lesions were scored visually and quantitatively by two independent observers. A visually PET-positive lesion was defined as uptake above background. For quantification, we used standardised uptake values (SUV): SUVmax, SUVpeak and SUVmean.

Results

Visual analysis showed an absolute positive and negative interobserver agreement for [18F]FES PET of 84% and 83%, respectively (kappa = 0.67, 95% CI 0.48–0.87), and 49% and 74% for [18F]FDHT PET, respectively (kappa = 0.23, 95% CI − 0.04–0.49). Intraclass correlation coefficients (ICC) for quantification of SUVmax, SUVpeak and SUVmean were 0.98 (95% CI 0.96–0.98), 0.97 (95% CI 0.96–0.98) and 0.89 (95% CI 0.83–0.92) for [18F]FES, and 0.78 (95% CI 0.66–0.85), 0.76 (95% CI 0.63–0.84) and 0.75 (95% CI 0.62–0.84) for [18F]FDHT, respectively.

Conclusion

Visual and quantitative evaluation of [18F]FES PET showed high interobserver agreement. These results support the use of [18F]FES PET in clinical practice. In contrast, visual agreement for [18F]FDHT PET was relatively low due to low tumour-background ratios, but quantitative agreement was good. This underscores the relevance of quantitative analysis of [18F]FDHT PET in breast cancer.

Trial registration

ClinicalTrials.gov, NCT01988324. Registered 20 November 2013, https://clinicaltrials.gov/ct2/show/NCT01988324?term=FDHT+PET&draw=1&rank=2.
Analysis and effect of conventional flasks in shaking culture of Escherichia coli
Authors: Takahashi Masato , Aoyagi Hideki
Published: April 2020

The circulation direct monitoring and sampling system (CDMSS) is used as a monitoring device for CO2 and O2 concentrations of bypass type in shake-culture flask. The CDMSS could measure kLa, an index for evaluating the performance of aerobic culture incubators, and kG, an indicator of the degree of CO2 ventilation in the flask gas phase. We observed that cylindrical flasks provided a different culture environment, yielded a much higher kG than the Erlenmeyer and Sakaguchi flasks, and yielded kLa equivalent to that by Erlenmeyer flask by setting the ring-type baffle appropriately. Baffled cylindrical flask used for Escherichia coli K12 IFO3301 shake culture maintained lower CO2 concentrations in the headspace than conventional flasks; therefore, CO2 accumulation in the culture broth could be suppressed. Cell growth in baffled cylindrical flask (with kLa equivalent to that of the Erlenmeyer flask) was about 1.3 and 1.4 times that in the Erlenmeyer and Sakaguchi flasks, respectively. This study focused on the batch culture at the flask scale and designed the headspace environment with low CO2 accumulation. Therefore, we conclude that redesign of flasks based on kLa and kG may contribute to a wide range of fields employing microorganism culture.
Degenerate polyexponential functions and type 2 degenerate poly-Bernoulli numbers and polynomials
Authors: Kim Taekyun , Kim Dae San , Kwon Jongkyum , Lee Hyunseok
Published: April 2020

The polyexponential functions were introduced by Hardy and rediscovered by Kim, as inverses to the polylogarithm functions. Recently, the type 2 poly-Bernoulli numbers and polynomials were defined by means of the polyexponential functions. In this paper, we introduce the degenerate polyexponential functions and the degenerate type 2 poly-Bernoulli numbers and polynomials, as degenerate versions of such functions and numbers and polynomials. We derive several explicit expressions and some identities for those numbers and polynomials.
Shear Capacity Contribution of Steel Fiber Reinforced High-Strength Concrete Compared with and without Stirrup
Authors: Yuan Tian-Feng , Yoo Doo-Yeol , Yang Jun-Mo , Yoon Young-Soo
Published: April 2020

This study presents the shear capacity of eco-friendly high-strength concrete (HSC) beams reinforced by 0.75% (by volume) of hooked steel fibers or shear stirrups with various spacings. Five large-scale HSC beams with steel fibers or stirrups were tested and investigated with respect to shear capacity, failure mode, and crack patterns. The test results indicate that all five tested beams finally failed by a shear-critical failure mode and that the use of 0.75 vol% of steel fibers significantly improved the shear strength although it decreased the diagonal crack angle of HSC beam in the case of without stirrups. There are some different properties compared with ACI 318-19 recommendation, but the use of 0.75 vol% steel fibers exhibited approximately 13.2% higher shear strength when compared with that of minimum shear reinforcement for the HSC beam. Furthermore, the shear capacity of steel fibers calculated by experimental data, and it was compared with several prediction equations. The prediction models containing fiber factor were more closely agreeable with test results with a minimum of 10.9% difference.
Long-term symptom control following resection of cervical lymphatic malformations: A case series
Authors: Khanwalkar Ashoke , Valika Taher , Maddalozzo John
Published: April 2020

Background

Previous literature has reported on the incidence of short-term complications following resection of cervical lymphatic malformations (LMs) in children, however no research has yet investigated the long-term symptomatic course in these patients. This study aims to provide families and providers with an understanding of expectations for long-term symptom control, specifically in association with subsequent upper respiratory infections (URIs).

Methods

A retrospective chart review produced a case series of patients who underwent resection of cervical LM at a pediatric tertiary care center between 2007 and 2016. Demographic data, disease characteristics, operative details, and postoperative care were evaluated. Telephone surveys were conducted to ascertain the course of postoperative symptoms at the surgical site.

Results

Forty-three patients responded to the telephone survey. Thirty-seven (86.0%) had at least one postoperative surgical site symptom during subsequent URIs, with 28 (65.1%) reporting redness, 34 (79.1%) reporting swelling, and 18 (41.9%) reporting pain. Patients who experienced any of these symptoms universally indicated that they developed soon after the surgical resection, and over half reported that they improved over time. Postoperative seroma was associated with swelling during subsequent URIs ( p = 0.04). Patients age 7 or were greater were more likely than those under 7 to report pain with URIs ( p = 0.006). All 8 patients with drain placement for at least 2 days reported swelling during subsequent URIs. The incidence of the queried symptoms did not vary significantly based on sex, stage, histology, surgical subsite, or presence of residual disease.

Conclusion

While preoperative symptoms associated with cervical LMs are also frequently encountered postoperatively, particularly in some patient subgroups, improvement over time should be expected.

Level of evidence

4
Do halophytes and glycophytes differ in their interactions with arbuscular mycorrhizal fungi under salt stress? A meta-analysis
Authors: Pan Jing , Peng Fei , Tedeschi Anna , Xue Xian , Wang Tao , Liao Jie , Zhang Wenjuan , Huang Cuihua
Published: April 2020

Background

Halophytes are better than glycophytes at employing mechanisms to avoid salt injury, but both types of plants can undergo damage due to high soil salinity. Arbuscular mycorrhizal fungi (AMF) can mitigate the damage from salt stress in both halophytes and glycophytes by enhancing salt tolerance and improving energy efficiency. However, variations in mycorrhizal symbiotic efficiency between halophytes and glycophytes were still poorly understood. Therefore, we evaluated the magnitude of AMF effects on plant growth and determined the mechanisms that regulate the growth response of halophytes and glycophytes by performing a meta-analysis of 916 studies (from 182 publications).

Results

Arbuscular mycorrhizal fungi significantly enhance biomass accumulation, osmolytes synthesis (soluble sugar and soluble protein), nutrients acquisition (nitrogen, phosphorus, and potassium ion), antioxidant enzyme activities (superoxide dismutase and catalase), and photosynthetic capacity (chlorophyll and carotenoid contents, photosynthetic rate, stomatal conductance, and transpiration rate). AMF also substantially decreased sodium ion acquisition and malondialdehyde levels in both halophytes and glycophytes under salt stress conditions. Mycorrhizal halophytes deploy inorganic ions (potassium and calcium ions) and limited organic osmolytes (proline and soluble sugar) to achieve energy-efficient osmotic adjustment and further promote biomass accumulation. Mycorrhizal glycophytes depend on the combined actions of soluble sugar accumulation, nutrients acquisition, sodium ion exclusion, superoxide dismutase elevation, and chlorophyll synthesis to achieve biomass accumulation.

Conclusions

Arbuscular mycorrhizal fungi inoculation is complementary to plant function under salt stress conditions, not only facilitating energy acquisition but also redistributing energy from stress defence to growth. Glycophytes are more dependent on AMF symbiosis than halophytes under salt stress conditions.
A case of Trousseau’s syndrome due to intrahepatic cholangiocarcinoma with an extremely high level of CA19-9
Authors: Sasaki Ryosuke , Ohya Yuki , Hayashida Shintaro , Maeda Yuto , Murahashi Shuei , Kumamoto Sayahito , Tsuji Akira , Shibata Hidekatsu , Kuramoto Kunitaka , Hayashi Hironori , Kuriwaki Kazumi , Iizaka Masayoshi , Nakahara Osamu , Inomata Yukihiro
Published: April 2020

Background

Trousseau’s syndrome is a cancer-associated thrombosis. Trousseau’s syndrome with cholangiocarcinoma is a rare condition with poor prognosis.

Case presentation

A 59-year-old female was admitted to our hospital with abdominal pain, headache, and nausea. Abdominal enhanced computed tomography revealed liver tumor, splenic infarction, and bilateral renal infarction. Multiple acute cerebral infarctions were also detected by magnetic resonance imaging. Her preoperative serum levels of carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) were > 120,000 U/mL and 589.6 ng/mL, respectively, which were extremely high. Histopathology after right hepatectomy revealed moderately differentiated adenocarcinoma consistent with intrahepatic cholangiocarcinoma. Her serum levels of CA19-9 were trending down to 9029.2 and 2659.8 U/mL at 1 and 3 weeks after surgery, respectively. However, at 7 weeks after surgery, her CA19-9 levels increased in the presence of positive imaging findings in the remnant liver, hilar lymph nodes, and peritoneal cavity. The initiation of combination chemotherapy including gemcitabine and cisplatin had a significant effect. The patient was doing well at 6 months after the surgery.

Conclusion

This rare case of Trousseau’s syndrome due to cholangiocarcinoma suggests that extremely high CA19-9 levels might be a pathogenic factor of this syndrome.
Striving for Agility in a VUCA Environment: The Analytic Hierarchy/Network Process
Authors: Peniwati Kirti
Published: April 2020

The business world is currently operating in an increasingly challenging environment characterized as volatile, uncertain, complex, and ambiguous (VUCA). If anything, the current COVID-19 crisis is a demonstration of this. What began as a health crisis has become a social and business crisis of large proportions.
Welcome to our first issue in 2020!
Authors: Mu Enrique
Published: April 2020

Welcome to our first issue in 2020! This volume marks our twelfth consecutive year of publication. While changes in the world were expected in this time, it has only been during the past few weeks that we have experienced social disruptive change on a global scale. The health crisis caused by COVID-19 is unprecedented and caught all of us by surprise. IJAHP expresses its solidarity with all of the people whose lives are being affected by the pandemic and express our wish for all to emerge from this crisis wiser and with a renewed faith in humanity.
High-dynamic-range areal profilometry using an imaging, dispersion-encoded low-coherence interferometer
Authors: Taudt Christopher , Nelsen Bryan , Baselt Tobias , Koch Edmund , Hartmann Peter
Published: April 2020

This work presents the design and characterization of an approach for areal surface profilometry with sub-nm axial resolution. The developed approach is based on a low-coherence interferometer enhanced by an dispersive element to control the axial resolution and measurement range. Optical path differences are detected by an imaging spectrometer where equalization wavelengths are determined as a basis for fitting spectra. This enables the acquisition of surface profiles with a length of up to 1.5 mm without mechanical scanning where a minimal resolution of 0.1 nm in an axial measurement range of nearly 80 µm was achieved. The resolution calculation was based on the standard deviation of measured feature heights. In addition to the system design, its capabilities are demonstrated on samples such as height standards.
Complete optical absorption in hybrid halide perovskites based on critical coupling in the communication band
Authors: Cheng Zi-qiang , Luo Xin , Xu Liang , Zhai Xiang , Wang Ling-ling
Published: April 2020

In order to remarkably enhance the absorption capability of (CH3NH3)PbI3, a tunable narrow-band (CH3NH3)PbI3-based perfect absorber based on the critical coupling with guided resonance is proposed. By using the finite-difference time-domain (FDTD) simulations, a complete absorption peak is achieved at the wavelength of 1310 nm. Moreover, we have compared the simulation results with theoretical calculations, which agree well with each other. By changing related structural parameters, the wavelength of absorption peak can be tuned effectively. Furthermore, the proposed absorber can tolerate a relatively wide range of incident angles and demonstrate polarization-independence. In addition to (CH3NH3)PbI3, the complete optical absorption in the other halide perovskites can be realized by the same mechanism.
Giant enhancement of white light emission from Ca9Ln(PO4)7:Eu2+,Mn2+ (Ln = La, Lu, Gd) phosphors achieved by remote aluminum reduction
Authors: Fang Yongzheng , Huang Yalan , Cao Yanrong , Zhao Guoying , Liu Yufeng , Huang Fuqiang , Sun Hong-Tao , Ou Haiyan , Hou Jingshan
Published: April 2020

A series of single-phase Ca9Ln(PO4)7:Eu2+,Mn2+ (Ln = Gd, La, Lu) phosphors with enhanced quantum yields were successfully developed through a topochemical reduction reaction strategy by using elemental aluminum as the reducing agent. Changes were observed both in the spectral shapes and photoluminescence intensities. New broadband emission covering the whole red region and centered at 630 nm from the remote Al reduced Ca9Ln(PO4)7:Eu2+ phosphors was observed, and their PL intensity was found to be greatly enhanced. The remote Al reduced Ca9Gd(PO4)7:Eu2+ reaches 4.3 times higher PL than the phosphors prepared by the traditional reduction method under CO atmosphere with the optimal Eu2+ dopant content. Finally, enhanced white-light emissions were gradually obtained by co-doping Eu2+ and Mn2+ in Ca9Ln(PO4)7, and the PLQY value is raised from extremely low to 61.6%. The mechanism for the changes of luminescence behavior was studied and discussed. This research also provides an enlightening reference for the preparation and development of high efficiency single-phase white light emitting phosphors.
An Investigation of Groundwater Contamination around Nsukka Municipality Dumpsite using the Resistivity Method
Authors: Nzemeka Olisah
Published: April 2020

An investigation using electrical resistivity method was conducted around a solid waste dumpsite at Nsukka in Nsukka L.G.A of Enugu State, Nigeria to investigate the level of groundwater contamination. Electrical Sounding (VES) and 2D resistivity imaging were used with a digital read out resistivity meter (ABEM SAS 1000) to acquire data in the area. A total of eight (8) sounding and six (6) 2D resistivity imagings were carried out in the area. A contaminant leachate plume was delineated in 2D resistivity sections as low resistivity zones while the VES shows the depth of aquifer. In 2D pseudosections where bluish colours with low resistivities (less than 20.80Ωm) with the depth ranging from 1.28m to 17.1m in the Line 1 and 2 are seen as contaminated zones. The rest of the lines are not contaminated because of their high resistivities (greater than 20.80Ωm). The result of the electrical resistivity survey also showed 4 - 5 layers geo-electric sections and an AA and AK type sounding curves. The VES result shows that VES 1A, 1B, 2A and 2B which are carried out on line 1 & 2 of the wenner lines showed signs of contamination with low resistivity values less than 20.80Ωm complementing the wenner results. The contamination has not yet got to where the aquifer is located on the lines. Since the depth to the aquifer ranges from 30.26m to 155.43m while maximum depth of contamination is 17.1m. It is believed that the leachate has not percolated down to the aquiferous zones as such aquifers are presumed to be free.
Cytokine Removal and Immunomodulation in COVID-19 Severe Pulmonary Respiratory Infection
Authors: Courville Karen , Bustamante Norman , Pecchio Maydelin
Published: April 2020

Coronavirus infection produces a cytokine storm in some patients, developing a moderate to severe clinical condition that is associated to increased mortality mainly because of severe pulmonary involvement. Elevated levels of IL-6 have been found in non-survivor patients.

In these patients, clearance of cytokines with extracorporeal therapies, Pulse High- Volume Hemofiltration together with adsorption columns Cytosorb, in short periods of time for 1 to 3 days, could help remove inflammatory cytokines allowing a downregulation of the inflammatory response; and, at the same time, treatment with low dose steroids, could give an opportunity for the host to reach homeostasis, decreasing lung damage and improving survival.
Kahoot aplicada en la evaluación sumativa en un curso de matemática discreta
Authors: Valles-Pereira Ricardo Enrique , Mota-Villegas Dorenis Josefina
Published: April 2020

En este artículo se describe una experiencia de aula, fruto de investigación, en la que se evaluó a un grupo de estudiantes del curso de Matemática Discreta en un tema fundamental como lo es la teoría de conjuntos y sus operaciones por medio de diagramas de Venn. Esto, mediante la incorporación de una herramienta tecnológica lúdica llamada Kahoot, la cual permite crear presentaciones/juegos interactivos en los que pueden participar una diversa cantidad de personas a la vez,desde dos personas hasta un amplio número, a través de dispositivos electrónicos. El objetivo fue despertar en el estudiantado interés por dominar los temas matemáticos y por agilizar la rapidez del pensamiento mental mediante el estímulo competitivo que supone comparar sus conocimientos con sus pares. Como metodología se realizó un estudio de campo sustentado en la revisión bibliográfica de los elementos teóricos de interés, en el que se empleó como muestra aquellos estudiantes que cursan la asignatura de Matemática Discreta afín a carreras de Ingeniería de Sistemas y Computación, en el período 2018-2019, en una universidad particular latinoamericana. Los resultados preliminares arrojaron una aceptación total de Kahoot como herramienta evaluativa y un buen porcentaje de respuestas correctas relativas al tema evaluado con dicha herramienta.
Is shadow education the driver of East Asia’s high performance on comparative learning assessments?
Authors: Rappleye Jeremy , Komatsu Hikaru
Published: April 2020

East Asian students consistently top comparative assessments of academic achievement. Yet, rather than attempting to develop more sophisticated understandings of this difference, the most common reaction is to attribute East Asian performance to longer study hours and/or the attendance at schools focused on academic skill enhancement and test preparation (i.e., juku). Herein we seek to contribute to a richer debate both by presenting new data and findings in relation to Japan, and by highlighting new analytical strategies to understand the relationship between East Asian performance and shadow education. Specifically, we highlight that comparatively high levels of achievement among Japanese students were apparent even at the level of fourth graders, even though juku attendance was low prior to this stage. This suggests that juku attendance is not the primary factor for the high academic achievement of Japanese students. The wider significance of these findings lies in countering both common portrayals of East Asian success and factually inaccurate information disseminated by organizations such as the OECD. In so doing, researchers are in better position to elaborate new, more sophisticated theories that explain East Asia’s consistently world- leading academic achievement.
Sintesis Senyawa Flavonoid dengan Menggunakan Bahan Dasar Senyawa Turunan Benzaldehida
Authors: Ismiyarto Ismiyarto , Matsjeh Sabirin
Published: April 2020

Sintesa 3,4-dimetoksi flavanon dengan menggunakan bahan dasar veratraldehida dan orto hidroksiasetofenon melibatkan dua tahap reaksi, yaitu reaksi Claisen-Schmidt dan siklisasi (adisi nukleofilik keton tak jenuh α, β). Pada reaksi Claisen-Schmidt, veratraldehida dan orto-hidroksiasetofenon bereaksi dalam suasana alkali menghasilkan 2’-hidroksi-3,4-dimetoksikalkon. Pada reaksi siklisasi, senyawa 2’-hidroksi-3,4-dimetoksikalkon mengalami siklisasi dalam kondisi alkali menghasilkan 3,4- dimetoksiflavanon. Analisis struktur senyawa flavanoid dilakukan dengan menggunakan spektrometer IR, UV-Vis dan 1H-NMR. Senyawa 2’-hidroksi-3,4-dimetoksikalkon yang dihasilkan berwama kuning dengan titik lebur 57°C dan rendemen 74,3%, sedangkan senyawa 3,4-dimetoksiflavanon yang dihasilkan berwama kuning pucat dengan titik lebur 80°C dan rendemen 72,0%.
Pengaruh Logam terhadap Status Darah Ikan
Authors: Muliani Hirawati
Published: April 2020

Polusi air merupakan penambahan material ke perairan yang akan mempengaruhi komposisi kimia, temperatur dan komposisi mikrobia. Beberapa jenis polusi ini, seperti benda-benda organik yang dapat membusuk, nutrisi berlebihan, padatan terlarut, bahan kimia toksik dan pencemaran termal, memiliki efek fisipologis terhadap ikan. Di antara bahan kimia toksik yang menyebabkan polusi tersebuut adalah logam. Terdapat logam tertentu yang dapat mempengaruhi status darah ikan, antara lain cadmium, timbal, merkuri dan tembaga
Pembuatan Katalis Pd-Ce/γ –Al2O3 dan Uji Aktivitas terhadap Oksidasi Metana
Authors: Suseno Ahmad , Triyono Triyono , Setiaji Bambang
Published: April 2020

Effects of Ce addition on Pt/γ - Al2O3 catalysts preparation and their catalytic activity on oxidation of methane have been investigated. In this study, the catalysts were prepared by impregnating chloride salt solution of palladium and sulphate salt of cerium on γ-AI2O3 support. Characterization of catalysts was conducted by gas sorption method to determine surface area, pore radius and pore volume. The test of catalytic activity on oxidation of methane was carried out in a flow reactor system at a temperature range from 350°C to 600°C. Products of reaction were analysed by non-dispersive IR spectroscopy. It was observed that the surface area, pore radius and pore volume decrease with the addition of cerium. The results of oxidation process showed that Pd-Ce/γ-Al2O3 catalyst can be used for oxidation of methane up to 90.62% conversion
Kinetika Fotodegradasi-UV PVC Beraditif Benzophenon
Authors: Siahaan Parsaoran
Published: April 2020

Telah diteliti kinetika fotodegradasi-UV pada PVC dengan penambahan aditif benzophenon. Film PVC dibuat dengan metode penguapan pelarut. Aditif benzophenon sebanyak 0,5% ditambahkan pada PVC. Film PVC difotodegradasi dengan sinar UV selama 30, 50, 70, 90, 110 jam. Tingkat degradasi ditentukan melalui pengukuran penurunan berat kering film, penurunan berat molekul, dan perubahan spektra UV dan IR. Hasil Penelitian menunjukkan bahwa penurunan berat kering PVC terfotodegradasi pada variasi waktu tertentu tanpa aditif adalah 4,91%, 6,20%, 7,97%, 9,29%, 10,07% dan dengan aditif benzophenon adalah 0,506%, 1,807%, 3,105%, 3,98%, 2,70%. Laju fotodegradasi PVC tanpa dan dengan aditif benzophenon masing-masing adalah 1,27 x 10-3 mg/jam dan 0,315 x 10-3 mg/jam, waktu paro fotodegradasi PVC tanpa aditif dan dengan aditif benzophenon masing-masing adalah 570 jam dan 2200 jam. Penurunan berat molekul PVC tanpa aditif dari 14080 menjadi 10882, 7400, 8870, 8044, 6360 dan dengan aditif benzophenon dari 14080 menjadi 13264, 12205, 12072, 11746, 11945 serta pola spektra UV dan IR yang berbeda. Dapat disimpulkan bahwa aditif benzophenon adalah inhibitor kinetika fotodegradasi-UV (stabilisator) terhadap PVC.
Isolasi dan Karakterisasi Pseudomonas Sp dari Limbah Fenol serta Kemampuan Biodegradasinya
Authors: Hendarko Sriani , Rukmi M.G. Isworo , Indrawati Agustina
Published: April 2020

Fenol diketahui sebagai senyawa hidrokarbon yang bersifat toksis, yang dalam konsentrasi tinggi dapat berbahaya bagi kehidupan mahluk hidup termasuk manusia. Pada konsentrasi yang tinggi, senyawa fenol dalam suatu lingkungan dapat didegradasi oleh mikroorganisme terutama oleh bakteri kelompok hidrokarbonolastik yang dapat menggunakan hidrokarbon sebagai sumber C untuk kehidupannya. Bakteri Pseudomonas adalah salah satu dari kelompok ini. Tujuan dari penelitian ini untuk mendapatkan isolat Pseudomonas dari sumber alam yang mampu mendegradasi senyawa fenol dan untuk menguji hubungan antara degradasi fenol dengan pertumbuhan bakteri Pseudomonas. Bakteri Pseudomonas yang digunakan dalam penelitian ini diisolasi dari limbah industri farmasi “P” di Semarang pada bulan Desember 1995. Tiga konsentrasi fenol yang berbeda diberikan dalam media yaitu 0,1 mg/L (F1), 0,2 mg/L (F2), 0,3 mg/L (F3) dan 0,0 mg/L sebagai kontrol. Pertumbuhan bakteri diuji dengan mengukur kerapatan optis pada panjang gelombang (λ) 640 nm, sedang perubahan kandungan fenol dalam media diuji menggunakan “Direct Photometric method” menurut Greenberg. Hasil dari penelitian ini menunjukkan bahwa Pseudomonas sp yang diisolasi dari limbah industri mempunyai kemampuan untuk mendegradasi senyawa fenol. Bakteri diisolasi dan diidentifikasi menggunakan Cowan dan Steel. Kerapatan optis tertinggi sebagai parameter pertumbuhan dijumpai pada F3 (0,2170), F2 (0,2076), F1 (0,1938)dan F0 (0,0315), sedang rata-rata waktu inkubasi adalah 16 jam (F1, F2, F3) dan 10 jam untuk F0. Kurva pertumbuhan pada F1, F2 dan F3 mulai menurun setelah 20 jam dan 14 jam untuk F0. Makin lama waktu inkubasi degradasi senyawa fenol dalam media makin tinggi.
Synthesis and Characterization of Triamine modified coated Iron Sand Hybrid Nanomaterials originating from Kendal Coast
Authors: Prasdiantika Ricka , Susanto Susanto , Kusumawardani Yustika
Published: April 2020

Nanomaterials have broad and unique applications in various fields. In this research, synthesis of Iron Sand Magnetic Hybrid nanomaterials coated with propyldiethylenetriammine modified silica (PB@SiO2@TA) originating from the coast of Muara Kencan, Kendal Regency. This study began with iron sand preparation, continued with activation, dispersing iron sand, then coating iron sand with propyldiethylenetriammine modified silica. The resulting product was characterized by X-Ray Fluorescence (XRF), Fourier Transform Infrared (FT-IR) Spectrophotometer, X-Ray Diffractometer (XRD), and Transmission Electron Microscope (TEM). The characterization results show that the iron sand of the coast of Muara Kencan Beach has a high iron oxide content (81.66%) with minerals in the form of magnetite. The characterization results also showed that the nanomaterial hybrid iron sand coated with propyldiethylenetriammine modified silica (PB@SiO2@TA) was successfully synthesized with a crystal size of 36.21 nm, with better particle dispersion than the prepared iron sand.
Microbial Growth as Determinant of Antibiotic Production with Biotic Elicitors Stimulation
Authors: Hardiyanti Citra , Khairullinas Khairullinas , Lumban Jeky Sasemar , Nugroho Titania Tjandrawati , Nurulita Yuana
Published: April 2020

An antibiotic-resistant and multidrug-resistant (MDR) issue open the role of researchers to continue to search for natural potential as a source of new antimicrobials. One of the potential fungi isolates that can produce antimicrobial active compounds from Indonesian tropical peat soils is Penicillium sp. LBKURCC34. In this study, the production of antimicrobial compounds from local isolates was carried out by batch fermentation method in liquid media with the addition of biotic elicitors to increase the extraction activity and yield. This study aims to optimize the results based on the time the elicitor is added. Staphylococcus aureus was used as a biotic elicitor, which was added on days 2, 3, and 4 in the production of antibiotics by fermentation incubation of 6-14 days. The antibiotic production media was extracted with ethyl acetate and evaporated. The antimicrobial test was carried out by the disk diffusion method against pathogenic bacteria Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Staphylococcus epidermidis using three crude extract contents (19; 38; and 57 µg/disc). Amoxicillin® was used as a positive control (10 µL/disc). The results showed that the addition of S. aureus biotic elicitor extended the log phase growth of the fungus Penicillium sp. LBKURCC34. The optimum condition of production was obtained by adding initiator treatment on the 3rd day for 14 days incubation with the highest yield and could inhibit the growth of all pathogenic microbes.
Bilangan Oksidasi dan Reaksi-Reaksi Mangan
Authors: Sriyanti Sriyanti
Published: April 2020

Telah dilakukan pembuatan tris (2,4-pentanadionato) Mangan (III), Kalium manganat dan Kalium permanganat untuk mempelajari bilangan oksidasi mangan. Dilakukan pula reaksi-reaksi sederhana terhadap mangan untuk mengamati mangan pada berbagai keadaan tingkat oksidasi. Hasil yang diperoleh menunjukan bahwa Mangan (II) stabil dalam suasana asam, Mangan (III) tidak stabil dan dapat distabilkan dengan pembentukan kompleks mangan-acetylacetonat, Mangan (IV) stabil dalam bentuk oksidanya (MnO2), Mangan (VI) atau manganat stabil dalam suasana basa kuat dan Mangan (VII) atau permanganat hanya stabil dalam suasana asam.
Penentuan Aktifitas Spesifik Tirosinase dari Kentang Solanum Tuberosum
Authors: Wuryanti Wuryanti , Sumardjo Damin , Budiatna Haris
Published: April 2020

Tirosinase dari umbi kentang (Solanum tuberosum) telah diisolasi secara fisik dan fraksinasi dilakukan dengan (NH4)2SO4 menjadi F1 (0-10%), F2 (10-20%), F3(20-30%) dan F4 (30-60%). Penentuan aktifitas enzim ini dengan menentukan serapan menggunakan spektrofotometer UV-Vis pada panjang gelombang 475 nm, sedang kadar protein ditentukan dengan metode Lawry. Hasil penelitian menunjujakan bahwa aktifitas spesifik tironase dari kentang adalah sebagai berikut: Ekstrak kasar 4,293u/mg, F1 (0-10%) 5,274 u/mg, F2 (10-20%) 5,579 u/mg, F3 (20-30%) 5,583 u/mg dan F4 (30-60%) 5,827 u/mg. Sebgai kesimpulan dari penelitian ini adalah bahwa fraksinasi dengan (NH4)2SO4 dapat dicapai hingga tingkat kemurnian 1,357 terhadap ekstrak kasar dengan spesifik aktifitas 5,827 u/mg.
Metoda Pembuatan Senyawa Organoiodium Turunan Sukrosa di Dalam Fraksi Air
Authors: Wibawa Pratama Jujur , Isniningsih Isniningsih
Published: April 2020

Dalam penelitian ini telah berhasil dibuat senyawa organoiodium turunan sukrosa di dalam fraksi air  dengan cara mereaksikan sukrosa, iodium dan fosfor merah di dalam set alat refluks pada suhu 98°C selama 15 menit. Pada akhir reaksi, campuran diekstraksi menggunakan n-heksana dan fasa atau fraksi air yang terbentuk dipisahkan dari fasa organiknya. Fasa air ini kemudian ditotolkan pada plat KLT yang dibuat dari gel silika 60 F254 dan dikembangkan dengan campuran butanaol : asam asetat : air (BAA, 4:1:5). Dari perlakukan ini diperoleh satu noda yang mempunyai Rf 0,6. Noda ini kemudian dikerok, diekstraksi menggunakan metanol dan kemudian dianalisis menggunakan spektrofotometer merah infra (MI). Noda ini memunculkan spektra IR yang khas pada bilangan gelombang 615,2 cm-1. Hal ini berarti ikatan C-I yang diharapkan berhasil terbentuk dan sekaligus menunjukkan bahwa fasa air tersebut mengandung senyawa organoiodium turunan sukrosa.
Sintesis Oktileugeniloksi Etanoat dari Eugenol
Authors: Lusiana Retno Ariadi , Siswanta Dwi
Published: April 2020

Telah disintesis senyawa ester oktil eugeniloksi etanoat dari bahan dasar eugenol dengan metode Furnish. Analisisstruktur dilakukan secarafisiko-kimia, seperti kromatografi gas, 1H-NMR, infra merah dan GC-MS. Hasilyang diperolehmenunjukkan bahwa senyawa oktil eugeniloksi etanoat berhasil didapatkan melalui reaksi esterifikasi
Identifikasi Asam Lemak Penyusun Minyak Biji Karet (Hevea Brasiliensis) Menggunakan GC-MS
Authors: Ismiyarto Ismiyarto , Prasetya Nor Basid Adiwibawa , Wibawa Pratama Jujur
Published: April 2020

Isolation of rubber seed (Hevea brasiliensis) oil have carried out by using soxhlet extraction with n-hexane as solvent. This research have been determined of fatty acid composition of rubber seed oil. Separation of free fatty acid from triglyceride done by ethanol 96 %. The oil phase was analysed by gas chromatography - mass spectrophotometer. It was resulted five chromatogram peaks of fatty acid methyl ester, there are methylester from palmitic acid (9.12%), linoleic acid (44.69 %), elaidic acid (44.69 %), stearic acid (8.89 %>) and 11,14-eicosadienoic acid (5.30 %) respectively.
Sintesis Garam SnCl2 dari Bahan Kemasan Berlapis Timah
Authors: Taslimah Taslimah , Ismail Ruslan , Sumardjo Damin
Published: April 2020

Telah dilakukan sintesis garam SnCl2 dengan bahan baku bahan kemasan berlapis timah. Sintesis dilakukan dengan merefluks oksida timah dengan larutan HCl, NaCl atau KCl selama 2 jam pada suhu 200 oC . Campuran disaring dalam keadaan panas, filtrat didinginkan, endapan yang terbentuk dipisahkan.Karakterisasi produk dilakukan dengan menentukan titik leleh dan daya reduksinya.Disimpulkan bahwa sebagai sumber ion Cl- yang baik berturut-turut HCl, KCl dan NaCl. Garam Yang dihasilkan berwarna putih keabu-abuan mempunyai kisaran titik leleh 243 – 248 oC dan bersifat sebagai reduktor.
Spektra Inframerah Spesi Teradsorpsi pada Katalis Pt/Aerosil
Authors: Anwar Chairil
Published: April 2020

Adsorpsi karbon monoksida, pirolidina dan butilamina pada Pt/Aerosil dan Aerosil dipelajari dengan menggunakan spektroskopi inframerah. Permukaan Pt/Aerosil dan Aerosil pada ruang hampa (10-6 mbar) selalu menyerap sinar pada daerah 3730 cm-1 yang ditunjukkan oleh munculnya pita tajam pada spektra. Pita serapan ini merupakan serapan dari vibrasi gugus OH yang dikenal sebagai silanol bebas (tidak membentuk ikatan hidrogen). Pita serapan ini akan hilang jika permukaannya ditambahkan amina yang berarti bahwa molekul amina terikat pada gugus OH melalui ikatan hidrogen. Penambahan karbon monoksida tidak mempengaruhi pita serapan ini. Karbon monoksida menimbulkan pita-pita serapan pada daerah antara 2100 cm-1 dan 1800 cm-1, hal tersebut menunjukkan bahwa amina dan karbon monoksida teradsorpsi pada sisi yang berbeda, molekul amina terikat pada gugus hidroksil sedangkan karbon monoksida terikat pada platinum.
Pengembangan Metode Penentuan Isoflavon Kadar Rendah dalam Limbah Cair Tahu Menggunakan Enzim NADH Oksidase
Authors: Sarjono Purbowatiningrum Ria , Danuri Hasim , Iswantini Dyah
Published: April 2020

Penentuan isoflavon asal limbah tahu telah dilakukan.Ekstrak kasar isoflavon asal limbah tahu diperoleh dengan cara menghidrolisis menggunakan HCl 4 N diperoleh rendemen sebanyak 4,81 g/l. Kadar isoflavon diukur menggunakan metode Graham (1999) yang sebelumnya dilakukan optimasi enzim NADH oksidase diperoleh panjang gelombang optimum pada 327 nm pada suhu 350C, pH 5, konsentrasi substrat optimum 100 μM, konsentrasi enzim optimum 0,3 U/ml. Kadar isoflavon dalam limbah tahu 0,123x103 ppm sedangkan kadar isoflavon kedelai sebesar 0,5921x103 ppm. Sehingga kadar isoflavon limbah tahu adalah sebesar 20% dibanding kadar isoflavon kedelai.
Evaluasi Model Langmuir-Hinshelwood untuk Kinetika Adsorpsi Besi(III) pada 2-Merkaptobenzotiazol-Zeolit Alam
Authors: Sriyanti Sriyanti , Taslimah Taslimah
Published: April 2020

Telah dibuat adsorben dengan mengimpregnasikan 2-merkaptobenzotiazol pada padatan pendukung zeolit alam yang sebelumnya telah dilapisi polistirena. Adsorben yang dihasilkan selanjutnya digunakan untuk mengadsorpsi besi (III) dalam medium air. Sebelum impregnasi zeolit diberi perlakuan fisikokimia, meliputi pemanasan 80 0C dalam campuran KMnO4 dengan H2SO4; KMnO4 dengan HCl dan KMnO4 dengan H2SO4, dilanjutkan dengan HCl. Kajian kinetika dilakukan dengan variasi waktu kontak terhadap banyaknya besi (III) yang teradsorpsi menggunakan metode batch. Model kinetika Langmuir-Hinshelwood digunakan untuk mengesti-masi besarnya konstanta laju, dan perubahan energi bebas adsorpsi. Sebagai evaluasi digunakan model kinetika adsorpsi melalui dua proses, cepat dan lambat. Hasil penelitian menunjukkan bahwa perlakuan awal KMnO4-H2SO4-HCl pada zeolit alam dapat dinyatakan sebagai cara paling efektif untuk menurunkan aluminium (dealu-minasi). Data adsorpsi ion besi (III) pada adsorben yang dibuat dari zeolit alam dengan perlakuan awal tersebut menunjukkan besi (III) teradsorpsi paling lambat baik dengan model Langmuir-Hinshelwood (k1=0,39x10-2 menit-1) maupun model adsorpsi dua proses (laju cepat (kc)= 3,66x10-2 menit-1, laju lambat (kl)= 0,106 menit-1). Dari data energi bebas, besi(III) teradsorpsi secara fisik.
Sintesis Metil Eugenol dan Benzil Eugenol dari Minyak Daun Cengkeh
Authors: Ngadiwiyana Ngadiwiyana , Ismiyarto Ismiyarto
Published: April 2020

Eugenol merupakan komponen utama minyak daun cengkeh dan biasa digunakan sebagai obat sakit gigi, demam dan penyusun minyak wangi. Pengembangan eugenol mulai banyak dilakukan, khususnya membuat senyawa turunannya. Salah satunya dengan melakukan reaksi alkilasi terhadap gugus hidroksil. Dalam penelitian ini, alkilasi eugenol dilakukan melalui dua tahap yaitu dengan membuat garam eugenolat melalui reaks antara eugenol dengan NaOH dan dilanjutkan reaksi garam eugenolat dengan metil iodida dan benzil klorida. Hasil-hasil reaksi dipisahkan dan dianalisis menggunakan spektroskopi IR dan kromatografi gas-spektroskopi massa. Hasil reaksi berupa larutan berwarna kuning dengan rendemen metileugenol dan benzileugenol masing-masing 53 % dan 47 %.