bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipid Profile and Prevalence of Dyslipidemia in Pre- and Postmenopausal Women in Yaounde, Cameroon
Authors: Gerard Nkeunen , Julie Judith Tsafack Takadong , Gustave Simo , Tambe Betrand Ayuk , Roger Ayangma Celestin , Bonglavnyuy Tume Christopher
Published: May 2019

Aims: Lipids serve several important physiologic functions like energy homeostasis or biosynthesis of hormone within the human body. The deterioration of lipid metabolism which is favoured by menopause is the source of cardiovascular diseases. This study aimed to determine the plasma lipid profile and dyslipidemia prevalence of some Cameroonian women.

Study Design: This was a cross-sectional study.

Place and Duration of Study: The enrollment took place at the Yaounde Military Hospital from November 2016 to July 2017.

Methodology: To achieve this goal, two sets of 105 postmenopausal and 127 premenopausal participants were enrolled in this study. 5ml of blood were collected on EDTA coated tubes from each participant. Enzymatic methods were used to evaluate total cholesterol, HDL cholesterol and triglyceride, while LDL cholesterol was determined using the Friedewald equation. These biological parameters were used to determine dyslipidemia. Thereafter, they were compared within age and year since menopause subgroups.

Results: There was no significant difference in the mean values of total cholesterol, HDL-C, LDL-C as well as triglyceride between premenopausal and postmenopausal women. The mean HDL-C concentration was stable in the age subgroups while the mean total cholesterol and LDL-C were slightly increasing as postmenopausal participants got older. LDL-C level was significantly higher in women who had been in menopause for more than 15 years. The overall dyslipidemia prevalence was 53%. Dyslipidemia was significantly higher in the subgroup of women who had freshly entered menopause.

Conclusion: Even though there was no change in the mean concentration of the plasma lipid parameters, of pre- and postmenopausal participants there was a general need to improve their lifestyle in order to reduce dyslipidemia prevalence.
Effect of Gibberellic Acid, Spacing and Nutrient Sprays on Growth and Flowering in Snapdragon (Antirrhinum majus L.) cv. Rocket Pink
Authors: Malik Sajid Ali , . Neelofar , Qadri Z. A. , Nazki Imtiyaz Tahir , Mir Shakeel Ahmad , Khan F. A. , Pukhta M. S.
Published: May 2019

An experiment was conducted to study the effect of different concentrations of gibberellic acid, spacing and nutrient sprays on vegetative and floral parameters of snapdragon (Antirrhinum majus cv. Rocket Pink) at Urban Technological Park, Habak, Srinagar, J&K, India during two successive years in 2017and 2018. Eighteen different treatments with 3 concentrations of gibberellic acid (0 ppm, 100 ppm and 200 ppm), 2 spacings (15 cm x 15 cm and 15 cm x 20 cm) and nutrient sprays (3 sprays, 4 sprays and 5 sprays) were replicated thrice in Completely Randomized Block Design. The investigation revealed that gibberellic acid at 200 ppm proved best among all in vegetative including height (91.07 cm), number of primary branches (4.11) and number of leaves (174.60) as well as in floral parameters including days to first inflorescence initiation (47.77), days to first inflorescence opening (50.81), days to 50% flowering (54.30), length of flower stalk (45.91 cm), length of inflorescence (38.80 cm), number of spikes per plant (7.72), number of florets per spike (22.35), number of fully developed florets (5.17), duration of flowering (52.62 days) and vase life (13.00 days).  Spacing of 15 cm x 15 cm proved better in terms of height (85.23 cm) in vegetative parameters and length of flower stalk (43.81 cm) and length of inflorescence (37.65 cm) in floral parameters while spacing of 15 cm x 20 cm proved better in number of primary branches (3.64) and number of leaves (170.68) as well as days to first inflorescence initiation (49.49), days to first inflorescence opening (52.33), days to 50% flowering (55.42), number of florets per spike (17.64), number of fully developed florets (4.47), duration of flowering (50.75 days) and vase life (10.71 days). Among different nutrient sprays application of 5 sprays proved best in all vegetative including height (87.06 cm), number of primary branches (4.26) and number of leaves (182.92) and floral parameters including length of flower stalk (42.88 cm), length of inflorescence (36.18 cm), number of spikes per plant (7.80), number of florets per spike (19.21), number of fully developed florets (4.67), duration of flowering (52.26 days) and vase life (10.92 days). While minimum days to first inflorescence initiation (49.05), first inflorescence opening (51.89) and 50% flowering were obtained by 3 nutrient sprays.
In vivo Antifibrotic Potential of Extracts of Acanthospermum hispidum DC. Evaluated in Wistar Rats Using Diethylnitrosamine
Authors: Yhi-Pênê N’do Jotham , Hilou Adama , Pare Dramane , Sombie Ernest Nogma , Guenne Samson , Tibiri André
Published: May 2019

Aims: Liver fibrosis is a chronic disease of the liver. This disease is a stage of passage to liver cancer. The objective of this work was to evaluate the ability of the ethanolic extract of Acanthospermum hispidum to block the progression of hepatic fibrosis induced in rats using diethylenitrosamine (DEN).

Study Design: Study of the antifibrotic potential of extracts of Acanthospermum hispidum.

Place and Duration of Study: In vivo tests were performed from September 2018 to January 2019. The animal model tests were carried out in the pet shop of the Institute for Health Sciences Research (IRSS) of Burkina Faso and in the Cytogenetics Laboratory (FSS/ISBA) of the Republic of Benin.

Methodology: The evaluation of the antifibrotic activity consisted in treating in wistar rats a liver fibrosis induced with the DEN which is a chemical agent whose effect on the liver has already been confirmed. As a result of the treatment, all animals were removed from the liver and blood. The livers were used for macroscopic and microscopic observations. Blood has been used for the evaluation of biochemical parameters in relation to fibrosis.

Results: The analysis of the results of the biochemical parameters in relation to the fibrosis showed that the ethanolic extract of Acanthospermum hispidum at the dose of 250 mg / kg made it possible to obtain an improvement of these parameters compared to the other batches of animals. These results have been confirmed by those of the anatomo-pathological studies.

Conclusion: The results of biochemical and histological analyzes revealed a capacity of Acanthospermum hispidum extracts to block the evolution of hepatic fibrosis in the rat. These results confirm the hepatoprotective potential of this medicinal plant used in traditional medicine in Burkina Faso.
Screening for Oral High-risk Human Papillomavirus (HPV) among a Pediatric Patient Population
Authors: Bowen Douglas , Kingsley Karl
Published: May 2019

Introduction: Human papillomavirus (HPV) is a known cancer-causing virus that has been primarily linked to cervical cancers. Recent studies have shown that HPV may also induce cancer in other tissues, including oral epithelia and mucosa. To determine the presence of oral HPV infection among pediatric patients, salivary samples were assessed to determine oral prevalence of high-risk HPV.

Methods: Using existing pediatric saliva samples from pediatric clinic patients (aged 6 - 16 years), this retrospective study involved isolating DNA for PCR screening for both high-risk strains of HPV (HPV16, HPV18). A total of n=98 patient samples were available for analysis.

Results: Demographic analysis of these samples revealed the majority were derived from females (63.2%) and mostly from Hispanics (54.1%). DNA was successfully isolated from 95.9% of samples (n=94/98) with an average concentration of 142.5 ng/uL. PCR screening demonstrated only a subset of patient samples harbored high-risk strains, HPV16 (n=9) and HPV18 (n=6), which represents 15.9% of the total sample population - and were concentrated among the older patients (>13 years old).

Conclusions: Although this retrospective study does not have a sufficient sample size to provide more robust analysis of other risk factors (race, sex, sociodemographic), these results to demonstrate that oral HPV infection may be successfully detected among a pediatric population. As more studies demonstrate oral HPV infection in children, these data are of significant value to other dental, medical, oral and public health professionals who seek to further an understanding of oral health and disease risk in pediatric populations.
Knowledge, Attitude, Practice towards Breast Cancer and Breast Self-examination among Female Undergraduate Students in Karachi, Pakistan
Authors: Rasool Saba , Iqbal Maham , Siddiqui Ammarah , Ahsan Ramna , Mukhtar Sahrish , Naqvi Shagufta
Published: May 2019

Aims: The study was aimed at investigating knowledge, attitude and practice towards breast cancer and breast self-examination among female undergraduate students in Karachi, Pakistan.

Study Design:  Cross Sectional study.

Place and Duration of Study: This study was conducted for a period of four months in different universities of Karachi, Pakistan.

Methodology: The study was done using a self-administered questionnaire. A total of 381 undergraduate students of medical and non-medical universities were included.

Results: The mean age of participants was 20.45 ± 3.67 years.  97% of the candidates had heard about breast cancer out of which only 65.4% were aware about its high prevalence rate in Karachi, Pakistan. A good proportion of candidates i.e. 78% of participants had good knowledge of breast self examination out of which only 43.8% knew how to perform it but just 24.9 % actually performed it.

20.5% of female population had made arrangements for breast screening once in their lifetime however many of the candidates (39.1%) never experienced any symptoms of breast pathology thus never felt the need to screen themselves.

Various signs and symptoms were considered as indications of breast cancer though lump as a sign was answered the most by 76.1% students. Out of the several risk factors of breast cancer 70.9% of candidates responded as family history the most common risk factor and early menstruation as a risk factor was 22.8% (the least).

44.4% of the aware candidates stated that they acquired this knowledge from social media. 21.5% had a positive family history. Mammography as a diagnostic modality was considered the most helpful by 61.4% population.

Conclusion: The study points out to the sufficient knowledge and attitude of breast cancer among female undergraduates in Karachi, Pakistan. However, they lacked the practice towards breast self examination. We expect that our results may provide useful data that could be used by the department of health in Karachi, Pakistan to formulate their health programs to increase the knowledge, attitude and practice towards breast cancer and breast self-examination.
Technological Analyze of Cassava Production in the City of Campos Dos Goytacazes – RJ
Authors: Borsoi Tales Neri , Jesus Freitas Silvio De , De Souza Paulo Marcelo , Barbosa Brito Patrick Martins , Da Silva Waldinei Souza , Salomão Soares Laura Pereira , Rosário Medeiros Samara Do , Da Silva Larissa Carvalho
Published: May 2019

This study analyzes the technological conditioning factors of cassava production in the municipality of Campos dos Goytacazes-RJ, seeking to elucidate the limitations and technological barriers that have contributed to the decline of crop production and productivity. A descriptive and quantitative methodology was adopted, in which the Survey method was used to analyze the technological factors through a questionnaire applied to 157 cassava producers in the field. The results evidenced the low degree of modernization of cassava in the municipality of Campos-RJ, intensive and extractive land use, generally produced on a small scale and with a low level of capitalization and productivity of work and land. This context seems to stimulate a vicious cycle, of low performance of the crops and profitability, low capacity of accumulation of resources, and capital and technological possibilities, favoring a gradual process of discouragement of the production. Without the possibility of gains and accumulation of income, the degree of uncertainty and risk tend to increase, as adversities and external forces make the permanence and perpetuation of the activity even more difficult, to emphasize the climatic factors and obstacles of commercialization and market. Thus, the research reinforces the need to evaluate technological alternatives that fit the local culture, as well as mechanisms that make them accessible to producers, such as: technical assistance, rural credit, social organization, among other public policies which aim to reduce the aggravation of rural activity in the municipality.
Image Analysis in the Evaluation of the Physical and Physiological Quality of Jiló (Solanum gilo) Seeds during Development
Authors: Prado Alves Marcus Vinicius , Von Pinho Édila Vilela De Resende , Prado Alves Gustavo Costa , Carvalho Maria Laene Moreira de , Santos Heloisa Oliveira dos
Published: May 2019

Currently, the X-ray image analysis of seeds has proved effective for the evaluation of the physical and physiological quality of the seeds, besides being a non-destructive method. The objective of this work was to evaluate the internal free area of jiló seeds (Solanum gilo) through the analysis of radiographic images and to relate the results with the germination of seeds in different stages of maturation. The seeds were harvested at 35, 40, 45 days after anthesis and 45 days after anthesis with 7 days at rest (45 DAAr). Seeds with free internal area ≤ 10% produced normal seedlings whereas seeds with an average free area above 10% produced abnormal or non-germinated seedlings. Seeds of fruits harvested at 45 DAA and seven days at rest showed a smaller internal free area and a formation of 100% of normal seedlings. The analysis of the radiographic images of jiló seeds allows the measurement of the free internal areas, as well as the determination of the relation between these and the germination.
Biopesticide Potentialities of Eagle Fern (Pteridium aquilinum) and Ricin (Ricinus communis) in the Protection of Vegetables Crops
Authors: Mala Carine , Kekeunou Sevilor , Djoukouo Nadia , Denis Zofou , Bassala Jean Paul Olina , Nukenine Elias
Published: May 2019

Introduction: Pesticides commonly used in crop protection are serious causes of ecological and sanitary disorders.

Aims: This present work investigates the biopesticide properties of Pteridium auquilinum and Ricinus communis in the protection of three vegetable crops Lactuca sativa, Solanum nigrum and Raphanus sativus.

Place and Duration of Study: The experimental tests were conducted on the site of BIONATURE (Bafoussam, Cameroon) from 24 June to 30 August 2017.

Methodology: Four types of preparations were made and bioefficacy tests consisted of contact treatments. Direct observations on the physical aspect of the plant, agronomic measurements, and pathology monitoring were carried out.

Results: The results show that the fermentation of the fern is complete after 5 days versus 8 days for the castor. The aqueous extracts of fern have insect repellent, insecticidal and fungicidal properties. Diluted maceration of fern (88.75%) was more efficient than the pure maceration (68%).

Conclusion: Manure and castor oil have insecticidal and repellent properties. The monitoring of pathologies after treatment reveals that castor oil is more effective than fern manure in control of gray rots and Tip burn attacks.
Details Geological Mapping and Petrological Characteristics of EL Shereik Study Area, River Nile State, North Sudan
Authors: Hassan Mahmoud Hussein , Amlas Mohamed , Al Zein Al Zein A. , Sheng Han Run
Published: May 2019

The present study focused on details geology of the lithostratigraphy, phenomena and petrogenesis, with full classification of rock units and correlate by the regional geology in the study area. The previous studies, focused on regional geology, which can be divided in Bayuda Terrane, represented by Dem El Tor Shear Zone (DTSZ), its Precambrian to Tertiary ages (isotopic signatures of later cooling 590 to 550 Ma), with dominated by metamorphic and intrusive rocks belonging to the Pre-Nubian basement complex. The study area lies at El Shereik, River Nile State, Sudan. It is characterized by low-lying bed plains, covered with superficial deposits, with an arid climate. The techniques of this work, represented in an official, field works and laboratory test, with used Land Sat Images ETM. And Nubian Arabian Shield, represented by the Keraf Shear Zone (KSZ), its Precambrian to Phanerozoic ages (Neoproterozoic, Pb isotope ages dating, of forms is -730 -710Ma and ended in -565Ma), with dominated by metamorphic, ophiolitic mélange, volcano-sedimentary sequences, and Phanerozoic sediments. But through this detailed surveyed, we discovered different types of rock units; they were found as accumulated and highly deformed, affected by various thrusting faults. collected more than 40 samples, through six traverses, for classification and petrographic studies and classified more than 9 types of rooks units didn’t mentioned before in previous study, all of them well exposed as following: metamorphic rocks, included, migmatites, calc-silicates, wollastonite, talc-schist, carbonaceous (dolomitic marble), amphibolites, graphitic schist, mica schist, quartzo-feldspathic schist, and grey gneiss, While the Igneous rocks, consisted of dykes, as dolerite,  trachy-basaltic, Rhyolite porphyry, pegmatites, diorite, and quartz veins, whereas the superficial deposits, included, of aeolian, fluvial, and collovial. These rocks extend and spread to the outside of the limits of the study area and most of them oriented parallel with KSZ SE - NW region and a few of them are oriented E-W, This is maybe due to the collusion of the contact boundary between KSZ and DTSZ Bayuda Tehran. Talc-schist, Wollastonite and graphitic schist, represent a strategic stockpile besides gold mining. Studies conducted with DTSZ, its old age, occurred before Neoproterozoic compared to KSZ. Because it has the first deformation of the folding of pre- KSZ proportion to the presence of folding in the west and east of the Nile zone, according to the border between Bayuda Terrane and Nubian Arabian Shield, as the suggest result. And the previous studies of the ages dating confirm it.
Cardioprotective Effect of Marine Astaxanthin on Doxorubicin-Induced Cardiotoxicity in Normal Rats
Authors: AlQahtani Ali A. , Osman Abdel-Moneim M. , Damanhouri Zoheir A. , Al-Kreathy Huda M. , Al-Malky Hamdan S. , Ramadan Wafaa S. , Alharthi Sameer E. , Kamel Fatemah O.
Published: May 2019

Background: Doxorubicin (DOX) is an effective antineoplastic drug indicated to treat many cancerous diseases but its clinical usefulness is limited by many side effects. The main and the most serious one is DOX induced cardiotoxicity. Many strategies have been tried to minimize this side effect such as addition of cardioprotective agent to DOX treatment protocols.

Aims: The aim of this work was directed to investigate whether marine astaxanthin (ATX), a xanthophyll carotenoid pigment with potent antioxidant effect, could protect heart against the cardiotoxicity induced by DOX.

Methodology: Forty Male Wister rats were divided into four equal groups and treated for one week as follow: Group I rats were treated with normal saline (2 ml/kg, x7, i.p.) and considered a control group. Group II rats were treated with ATX (40 mg/kg, x7, i.p.). Group III rats were treated with normal saline (2 ml/kg, x7, i.p.) and a single dose of DOX (20 mg/kg, i.p.) at day 7. Finally, group IV rats were treated with ATX (40 mg/kg, x7, i.p) and with a single dose of DOX (20 mg/kg, i.p.) at day 7. After 24 and 48 hrs of treatment, rats were anesthetized and prepared for collection of blood samples and heart isolation. The cardioprotective effect of ATX against DOX induced cardiotoxicity were evaluated by measurement of the serum level of cardiac enzymes CPK by colorimetric assay and CK-MB by Eliza. Also the levels of serum total antioxidant capacity (TAC) were measured colorimetrically. In addition, the Malondialdehyde (MDA), reduced glutathione, glutathione peroxidase (GPx) levels and superoxide dismutase (SOD) were determined in heart tissues homogenate by colorimetric method. In addition, Heart sample were taken for histopathology studies.

Results: The Addition of ATX to DOX significantly (p<0.05) decreased the serum level of cardiac enzymes (CPK, CK-MB) and increased the serum total antioxidant capacity in compare with these levels in sera of rats treated with DOX only. This addition also significantly decreased the level of malondialdehyde and increased the reduced glutathione and glutathione peroxidase and superoxide dismutase significantly in the heart tissues homogenate in compare to corresponding levels in rats treated with DOX alone. Histopathological investigation of cardiac tissues confirmed the biochemical studies, where addition of ATX to DOX treatment protocol showed that the fragmentation of the muscle fiber revealed normal with central vesicular nuclei and prevented a marked disruption of normal cardiac architecture which resulted from DOX treatment.

Conclusion: Marine astaxanthin provides excellent cardioprotective effect against doxorubicin induced cardiotoxicity in rats.
Diagnostic Value of Distal Forearm Densitometry for Osteoporosis; Alone or Add to Hip and Spine Densitometry?
Authors: Moghimi Nasrin , Rahmani Khaled , Rajabnia Mohsen
Published: May 2019

Background: In most centers of the world, for diagnosing osteoporosis is used densitometry in hip and spine, but due to the high prevalence of distal forearm fracture and osteoporosis as its main etiology and on the other hand, evaluation of the distal forearm densitometry as an predictor indicator for axial osteoporosis, evaluate the diagnostic value of distal forearm densitometry for osteoporosis; alone and with adding to hip and spine densitometry.

Materials and Methods: This cross-sectional descriptive-analytic study was carried out on 250 patients referring to Sanandaj densitometry center from September 2017 to September 2018. For the studied subjects, BMD was performed by DXA method in three regions of hip, spine and distal forearm. Data were analyzed using independent t-test, fisher exact test, chi-square test and logistic regression test using SPSS v. 23 software.

Results: In this study, 68 cases (27.2%) in the spine region, 38 cases (15.2%) in the hip and 85 cases (34%) in distal forearm were osteoporotic. Based on the results of this study, using the conventional method (hip and spine) in comparison with the studied method (hip, spine and distal forearm), 29 (11.6%) of those cases with osteoporosis are not diagnosed. Distal forearm densitometry alone in comparison with the conventional method has diagnostic sensitivity 74.66%, specificity 83.43%, positive predictive value (PPV) 65.88% and negative predictive value (NPV) 88.48%.

Conclusion: Adding distal forearm densitometry to conventional method significantly increasing diagnostic sensitivity of osteoporosis and would prevent misdiagnosis. Distal forearm densitometry can use as a predictor indicator of axial osteoporosis.
Biotreatment of Crude Oil Contaminated Soil
Authors: Popoola B. M. , Olanbiwonninu A. A.
Published: May 2019

Biodegradation of hydrocarbons by microorganisms represents one of the primary mechanisms by which petroleum and other hydrogen pollutants are eliminated from the environment. This work was carried out on the effect of microorganisms on the biotreatment of oil in crude oil contaminated soil.

Microorganisms were isolated from two experimental soil samples contaminated with Bonny Crude and normal uncontaminated soil as a control over a period of seven months. The microbial as well as the physico-chemical parameters of the soil samples were all analyzed using standard methods. Changes in total petroleum hydrocarbon level were measured appropriately. Treatments used were the microbial isolates.

Forty-four microorganisms were isolated from the contaminated soils and identified as species of Pseudomonas (7), Flavobacterium (6), Bacillus (8), Proteus (4), Klebsiella (1), Pencillium (5), Aspergillus (7), Fusarium (3), Trichypton (2) and Neurospora (1). Ten of the forty-four isolates had ability to degrade crude oil in the laboratory. On contamination a value of 1.0X105 cfu/g in microbial counts were obtained followed by a subsequent increase in population levels after a period of 2months with a value of 1.0X106 cfu/g. Oil application to the soil resulted in an increase in total petroleum hydrocarbon from 0.31 ppm to 5.53 ppm; organic matter from 0.41% to 7.34%; available phosphorus from 1.75 ppm to 2.84 ppm. The treatment measures all showed progressive decrease in oil concentration in the soil. Mixture of bacterial and fungal isolates as a treatment measure proved to be more favourable above all others, it brought the concentration from 5.53 ppm to 0.31 ppm after a period of 5 weeks of treatment, which is same value with the normal soil (uncontaminated).

Species of Pseudomonas, Bacillus, Flavobacterium, Proteus, Klebsiella, Penicillium, Aspergillus, Fusarium, Trichyphyton and Neurospora had potential for the degradation of bonny crude oil. They could therefore be employed in environmental cleanup of petroleum spill site.
Catalytic Dehydrogenation of para-Diethyl Benzene to para-Divinyl Benzene over Iron Oxide Supported Catalyst
Authors: Srivastava Vivek Kumar , Sharma Nagesh , Jasra Raksh V.
Published: May 2019

The vapor-phase catalytic dehydrogenation of para-diethyl benzene (PDEB) to para-divinyl benzene (PDVB) with super-heated steam as a diluent was investigated using alumina supported iron oxide catalyst system. During the catalytic dehydrogenation reaction, ethyl styrene (EST) and thermal cracking products were observed as side products. It was found that various reaction parameters influence the rate of dehydrogenation reaction. However, the reaction is favored by high temperature and low reaction pressure. Moreover, addition of potassium into iron-oxide catalyst acts as a promoter and thereby increases the efficiency of the catalyst. The conversion of PDEB and yield of PDVB also increases as the Water/PDEB flow ratio increases.
Evaluation of Enzyme Kinetic Parameters to Produce Methanol Using Michaelis-Menten Equation
Authors: Zainol Norazwina , Ismail Siti Natrah
Published: May 2019

Determination of kinetic parameters of enzymes is important in biotechnology research. It is also one of the most challenging processes in methanol production. The activity of enzyme is determined in term of initial rates at various substrate concentrations. The enzymatic hydrolysis of methanol by pectin methyl esterase (PME) enzyme was investigated at 25 °C and pH 9 over the reaction time range from 0 to 90 min. In this study, the parameters of the enzyme's kinetic, KM and Vmax were directly determined using a modified Michaelis-Menten equation by applying the Lineweaver-Burk plots. Besides, nonlinear regression of Michaelis-Menten equation was calculated based on Euler’s and Runge-Kutta 4th order methods by using Solver supplement application. The result of kinetic constant was tested by comparing the experimental data with model predictions. It was found that Euler and Runge-Kutta method was successful in determining the kinetic parameter rather than Lineweaver-Burk plot. The application of the Michaelis-Menten equation describes the enzyme kinetic very well. From the kinetic analysis, it showed the good agreement between the result obtained and the predictions model in the production of methanol using PME enzyme.
Comparison of Lewis Acidity between Al-MCM-41 Pure Chemicals and Al-MCM-41 Synthesized from Bentonite
Authors: Ali-Dahmane Tewfik , Brahmi Lamia , Hamacha Rachida , Hacini Salih , Bengueddach Abdelkader
Published: May 2019

This study focused on the Lewis acidity of Al-MCM-41 prepared from bentonite (Al-MCM-bentonite) as silica and aluminum source simultaneously. This acidity was compared with Al-MCM-41 synthesized from pure chemicals reagents (Al-MCM-standard). Structural analysis showed that the substitution of the silicon atom by the aluminum atom decreases the structural order of Al-MCM-standard, whereas Al-MCM-bentonite has a better structural organization. The Lewis acidity of the Al-MCM-bentonite was evaluated in allylation reaction of benzaldehyde with allyltrimethylsilane and pyridine adsorption experiments. The results showed that the difference in acidity between Al-MCM-standard and Al-MCM-bentonite is due to the amount of aluminum incorporated into the framework of our mesoporous materials. According to the EDX analysis, the incorporation of aluminum in Al-MCM-standard (Si/Al = 13.47) is more important than in Al-MCM-bentonite (Si/Al = 43.64). This explains the low acidity of Al-MCM-bentonite, and the moderate yields in the allylation reactions of benzaldehyde with allyltrimethylsilane.
Facile Template In-Situ Fabrication of ZnCo2O4 Nanoparticles with Highly Photocatalytic Activities under Visible-Light Irradiation
Authors: Tan Vu T. , Vinh La The , Khiem Tran Ngoc , Chinh Huynh Dang
Published: May 2019

High specific surface area ZnCo2O4 nanoparticles were prepared via a sacrificial template accelerated hydrolysis by using nanoparticles of ZnO with highly polar properties as a template. The obtained ZnCo2O4 nanoparticles were characterized by the method of scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurements, Transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The obtained nanoparticles were performed as a photocatalyst for the degradation of methylene blue in aqueous solution under visible irradiation. The photocatalytic degradation rate of methylene blue onto the synthesized ZnCo2O4 was higher than that of commercial ZnO and synthesized ZnO template.
Effects of Ion Exchange Process on Catalyst Activity and Plasma-Assisted Reactor Toward Cracking of Palm Oil into Biofuels
Authors: Istadi Istadi , Buchori Luqman , Anggoro Didi Dwi , Riyanto Teguh , Indriana Anindita , Khotimah Chusnul , Setiawan Fachmy Adji Pangestu
Published: May 2019

Biofuels can be produced through a conventional catalytic cracking system and/or a hybrid catalytic-plasma cracking system. This paper was focused on studying effect of Na+ ion exchange to HY-Zeolite catalyst on catalyst performance to convert palm oil into biofuels over a conventional continuous fixed bed catalytic cracking reactor and comparing the catalytic cracking performance when carried out in a continuous hybrid catalytic-plasma reactor. The catalysts were characterized by X-ray Diffraction (XRD) and Bruneuer-Emmet-Teller (BET) surface area methods. The biofuels product were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to determine the hydrocarbons composition of biofuels product. From the results, ion exchange process of Na+ into HY-Zeolite catalyst decreases the catalyst activity due to decreasing the number of active sites caused by blocking of Na+ ion. The selectivity to gasoline ranges achieved 34.25% with 99.11% total conversion when using HY catalyst over conventional continuous fixed bed reactor system. Unfortunately, the selectivity to gasoline ranges decreased to 13.96% and the total conversion decrease slightly to 98.06% when using NaY-Zeolite catalyst. As comparison when the cracking reaction was carried out in a hybrid catalytic-plasma reactor using a spent residual catalytic cracking (RCC) catalyst, the high energetics electron from plasma can improve the reactor performance, where the conversion and yield were increased and the selectivity to lower ranges of hydrocarbons was increased. However, the last results were potential to be intensively studied with respect to relation between reactor temperature and plasma-assisted catalytic reactor parameters. Copyright © 2019 BCREC Group. All rights reserved
Antennas for Mobile Communications
Authors: Fujimoto Kyohei
Published: November 2024

Antennas used for mobile communications are not necessarily specialized types of antenna; ordinary antenna types can be used. However, there are several distinctions in performance between mobile and fixed communications with respect to design methodology for antennas in mobile communications, including variations of field strength, varied environmental conditions, mechanical and physical robustness, and mechanical and electrical system performance.
Dielectric Measurement
Authors: Bartnikas R.
Published: November 2024

Dielectric measurements are concerned with the characterization of solid, liquid, and gaseous insulating materials over a wide range of DC and AC conditions at different frequencies temperatures, field strengths, and pressures, under differing environments.

Space does not permit a detailed description of all the dielectric measurement procedures and, consequently, only a cursory presentation is made.

Accordingly, the presentation is necessarily confined to a concise description of the most common methods of dielectric measurement employed currently.
Microwave Measurements
Authors: Ferrero Andrea , Teppati Valeria , Pisani Umberto
Published: November 2024

This contribution discusses microwave measurements principles and techniques. The first section describes power, spectral, and noise measurements. Section 2 discusses network analyzer measurements, calibrations, and time‐domain reflectrometry. Finally, some advanced measurement techniques, as load‐pull and time‐domain waveform characterization, are described.
Finline Components
Authors: Menzel Wolfgang S.
Published: November 2024

Finline is a planar transmission line suspended in theEplane of a metal waveguide. The electromagnetic field is guided by a slot in the finline metallization. This contribution gives an overview of the possibilities of realizing passive as well as active components based on this type of transmission line. The article begins with a discussion of filters, directional couplers, and antennas and nonreciprocal components are mentioned later. It continues with a discussion of diode‐based components such as detectors, p‐i‐n diode attenuators or switches, mixers, and phase shifters. After a short remark on oscillators and amplifiers, a number of integrated components and front ends are presented.
Electromagnetic Materials
Authors: Choudhury Pankaj K.
Published: November 2024

This article describes the electromagnetic properties of certain types of mediums or materials in which the process of electromagnetics takes place. The introductory part discusses the evolution of electromagnetics based on theories and experiments by the pioneering scientists in the past. The following portions of the article deal with the different types of mediums, including isotropic and anisotropic dielectrics, conductors, semiconductors, superconductors, electrooptic, and optically active mediums. The fundamentals of magnetic materials are described in greater detail, explaining the mechanisms of magnetization and special materials such as ferrites. Bianisotropic materials and their constitutive equations are also discussed. Here, the focus is on some of the fundamental aspects of the constitutive characterization of bianisotropic mediums. The last three sections describe the basics and important applications of the phenomena of magnetostriction, piezoelectricity, and metamaterials.
Investigating the effects of table movement and sag on optical surrogate‐driven respiratory‐guided computed tomography
Authors: Lackner Niklas , Dietrich Lou , Karius Andre , Fietkau Rainer , Bert Christoph , Szkitsak Juliane
Published: November 2024

Purpose

Respiratory‐guided computed tomography (CT) typically employs breathing motion surrogates to feed image reconstruction or visual breathing coaching. Our study aimed to assess the impact of table movements and table sag on the breathing curves recorded in four‐dimensional (4D) CT and deep‐inspiration breath‐hold (DIBH) CT.

Methods

For breathing curve measurements, static and dynamic phantom scenarios were used. Breathing curves were recorded using three different surrogate systems and the impact of table sag due to weights of up to 130 kg was analyzed and compared to a non‐weighted setting, respectively. The calibration procedure of the system used as an input for the visual coaching device used for clinical DIBH CT scans was adapted. We evaluated corresponding breathing curves acquired during DIBH and 4DCT scans of altogether 70 patients using various stability metrics.

Results

The various surrogate systems showed consistent table sag measurements below 4 mm, even under loads up to 130 kg, compared to a reference scan conducted without additional weight. Higher weight loads were related to steeper table sag fall‐offs towards the deepest table position. For DIBH CT scans, the visual guidance was heavily affected by artifacts. This resulted in breathing threshold limits, which could not be achieved by 48% (n = 21) of the, respectively, examined patients. Using the new calibration workflow, the baseline drift was compensated better and 90% (n = 20) of the addressed patients stayed within the thresholds. The evaluated table sag in clinical 4DCT scans (n = 29) stayed below 3 mm compared to the non‐weighted situation.

Conclusion

Table movement and sag can impact breathing curves recorded by different surrogate systems. Correcting table movement and sag artifacts is crucial for reliable breathing curve acquisition in respiratory‐guided CT.
Evaluation of an improved picket fence style test for routine MLC positional QA
Authors: Barnes Michael , Standen Therese , Blackmore Renee , Greer Peter
Published: November 2024

Purpose

The aim was to develop and evaluate an EPID‐based MLC positional test that addresses known weaknesses of the picket fence test and has sufficient accuracy so that the AAPM MPPG 8.b. MLC position action limit of ± 0.5 mm can be implemented.

Methods

Weaknesses and inaccuracies in the picket fence test were identified and a new test plan and analysis algorithm named stakitt was developed. Stakitt was evaluated for repeatability and for sensitivity on the Varian TrueBeam linac with both Millennium MLC and HDMLC and on a Varian Clinac with Millennium MLC. Sensitivity was tested via deliberate introduction of errors into the test plan of magnitude: ± 0.1, ± 0.5, ± 1.0 and ± 1.5 mm. Measured sensitivity was compared to published sensitivity of the picket fence test. Additionally, a use case was presented based on results from a TrueBeam linac to highlight the effect of MLC backlash on MLC positions at non‐zero gantry angles.

Results

Repeatability was observed to within 0.04 mm (3 SD) with the TrueBeams being more repeatable than the Clinac. The deliberately introduced errors were accurately measured to within 0.28 mm and were comparable to the traditional picket fence. Reduced accuracy was recorded for the HDMLC small leaves, which was attributed to an apparent variation in measured leaf width across the range of travel, which impacted the measurement of the leaf tip position. The clinical use case demonstrated variability in MLC leaf positions between gantry 90° and gantry 270° that were of the magnitude of the MLC backlash.

Conclusion

The stakitt test addresses the weaknesses of the picket fence test and has accuracy appropriate for implementation of a ± 0.5 mm action limit. However, such an action limit may not be currently practical at non‐zero gantry angles due to the impact of MLC leaf backlash.
Automated hippocampal sparing whole brain radiotherapy with simultaneous integrated boost for multiple brain metastases: Halcyon, HyperArc on TrueBeam, and coplanar TrueBeam
Authors: McCarthy Shane , Clark Ryan , Magliari Anthony , St. Clair William , Pokhrel Damodar
Published: November 2024

Purpose

To demonstrate the ease and feasibility that hippocampal sparing whole brain (WB) simultaneous integrated boost (HSWB‐SIB) plans can be generated using knowledge‐based planning and Eclipse Scripting Application Programming Interface (ESAPI) for three different modalities, HyperArc on TrueBeam (TB‐HA), a coplanar beam arrangement on TrueBeam (TB‐Co), and the ring‐mounted Halcyon LINAC (Hal).

Methods

Twelve patients with 2–14 brain metastases were retrospectively replanned for HSWB‐SIB using a published HSWB RapidPlan model with modifications for the automated addition of SIB to metastases. Prescribed dose was 30 Gy to the WB planning target volume (PTV) and 50 Gy to the metastases in 10 fractions. Eclipse treatment planning system (v16.1) was used with a 6 MV‐FFF beam and Acuros XB dose algorithm.

Results

The methodology was successfully used for all modalities, generating plans in under 30 min. The plan doses were normalized to the WB PTV D95% receiving 30 Gy. Reporting values in the order of Hal, TB‐Co, and TB‐HA: The WB PTV received a V48 Gy of 4.58, 3.98, and 4.45 cc with statistically insignificant differences (p = 0.806). The boost PTVs received a D95% of 50.60, 50.43, and 51.13 Gy with statistically significant comparisons between TB‐HA and the other two modalities (p = 0.005). The hippocampus maximum dose was 11.81, 11.51, and 11.13 Gy with no statistically significant comparisons (p = 0.105). All other oragns‐at‐risk (OAR) doses were clinically acceptable. The modalities were evaluated using a dosimetric scorecard, achieving average scores of 84.85%, 86.45%, and 87.39%. End‐to‐end testing ensured the deliverability of the HSWB‐SIB plans for all modalities.

Conclusion

The novel modification of the preexisting HSWB RapidPlan model with the automated inclusion of SIB objectives allows for easy, intuitive planning of complex HSWB‐SIB treatments. All modalities demonstrated can be used with clinically comparable results. Other institutions are recommended to pursue and validate this HSWB‐SIB technique to increase the accessibility of a single‐course of high‐quality treatment for patients with multiple brain lesions.
In Situ Asymmetric Patterning for Information Encryption
Authors: Chen Chong , Ai Bin , Wang Yu , Xiao Zifan , Xiao Ge , Zhang Gang
Published: November 2024

Here, Ag nanoparticle asymmetric assembly arrays (NAAAs) are realized through a facile and inexpensive in situ asymmetric patterning process based on plasmonic nanochemistry. The growth of Ag NPs follows the asymmetric maximum plasmonic field region of Au nanoholes under light irradiation, as demonstrated by finite‐difference time‐domain (FDTD) simulations. Ag NAAAs exhibit unique Fano resonance modes due to the asymmetric arrangement of the nanoparticles. The size and morphology of Ag NAAAs can be systematically tuned by adjusting the reaction duration, deposition parameters, and etching conditions. Various multiscale patterns from macroscopic to submicron scales can be precisely obtained in combination with photolithography. Ag NAAAs can serve as excellent surface‐enhanced Raman scattering (SERS) substrates with an enhancement factor of up to 2.79×109. Combining the adjustable asymmetric morphology and editable patterning capabilities of multiscale Ag NAAAs, the application of anti‐counterfeiting labels integrating structural, molecular, and pattern/text information is realized. In addition, asymmetric patterning techniques can be used to create Au NAAAs and applied on flexible polydimethylsiloxane substrates, thereby enhancing the versatility of the anti‐counterfeiting labels in practical applications.
Organoids of Musculoskeletal System for Disease Modeling, Drug Screening, and Regeneration
Authors: Chen Weicheng , Liu Dachuan , Lu Kai , Xu Mengping , Li Di , Yan Wei , Chen Song , Li Bin
Published: November 2024

Musculoskeletal diseases have emerged as the leading cause of disability worldwide, with their prevalence increasing annually. In light of this escalating health challenge, organoids, an emerging technology in tissue engineering, offer promising solutions for disease modeling, drug screening, regeneration, and repair processes. The successful development of musculoskeletal organoids represents a significant breakthrough, providing a novel platform for studying musculoskeletal diseases and facilitating the discovery of new treatments. Moreover, organoids serve as valuable complements to traditional 2D culture methods and animal models, offering rich insights into musculoskeletal biology. This review provides an overview of organoid technology, outlining the construction processes of various musculoskeletal organoids and highlighting their similarities and differences. Furthermore, the challenges associated with organoid technology in musculoskeletal systems are discussed and insights into future perspectives are offered.
Dual‐Enhanced Nanohybrids for Synergistic Photothermal and Photodynamic Therapy in Cancer Treatment with Immune Checkpoint Inhibitors
Authors: Lee Dabin , Sun Hyungjin , Bang Jieun , Heo Tae‐Young , Pham Duong Thi‐Thuy , Jang Jong Dae , Han Young Soo , Shin Tae Joo , Choi Soo‐Hyung , Park JaeHong , Doh Junsang , Park Juhyun
Published: November 2024

This study presents a nanohybrid that simultaneously improves both photothermal (PT) and photodynamic (PD) effects for cancer therapy. The conjugated polymer nanoparticle (CPN) comprises of p‐type conjugated polymer as a photosensitizer, charge donor, and PT agent, n‐type conjugated polymer as a charge acceptor and PD agent, and Au nanoparticles (NPs) as a PT agent. This nanohybrid is assembled through a film dispersion process using a hydrophobically modified phospholipid, producing a high yield of uniform hybrid NPs in a short timeframe, and displays exceptional photothermal and photodynamic effects, when activated at a single near‐infrared wavelength. Photophysical analysis indicates that the inclusion of Au NPs enhances nonradiative exciton relaxation, while the incorporation of a n‐type conjugated polymer boosts photoinduced charge transfer and potentially contributes to the charge‐recombination mediated triplet‐state formation for an enhanced generation of reactive oxygen species. During phototherapy, the nanohybrid demonstrates the most effective suppression of primary tumor growth and significantly boosts anti‐tumor immune responses owing to its simultaneous photothermal and photodynamic effects. Furthermore, when combined with immune checkpoint inhibitors, nanohybrid treatment minimizes tumor sizes while maximizing survival rates in mice. Thus, the nanohybrid represents a promising nanoplatform for combination phototherapy in cancer treatment.
Macro‐Superlubricity Induced by Tribocatalysis of High‐Entropy Ceramics
Authors: Du Changhe , Yu Tongtong , Sui Xudong , Zhang Zhengfeng , Cai Rongsheng , Zhang Liqiang , Feng Yange , Feng Min , Zhou Feng , Wang Daoai
Published: November 2024

Macroscale superlubricity has attracted considerable attention as a promising strategy to minimize frictional energy dissipation and achieve near‐zero wear. However, realizing macroscale superlubricity with prolonged durability remains an immense challenge, particularly on engineering steels. Current superlubricants render steel surfaces susceptible to corrosion, causing severe wear and superlubrication failure. Herein, high‐entropy ceramics (HEC) with catalytic properties are innovatively introduced to prevent corrosion of engineering steels and achieve macro‐superlubricity through tribo‐catalytic effect. Furthermore, this catalytically induced superlubricity system exhibits an ultra‐low friction coefficient of 0.0037 under contact pressure up to 1.47 GPa, an ultra‐long cycle lifetime of 1.25 × 106 cycles (corresponding sliding distance up to 5 km), and an extremely low wear rate of 3.032 × 10−10 mm3·N−1·m−1 on the HEC surface. Based on the experimental analysis and theoretical simulation, the in situ formed HEC nanocrystals reduce the Gibbs free energy of hydrolysis of PA molecules into inositol and phosphoric acid molecules in the lubricant. Notably, the hydrolysis products favorably contributed to the reduction of shear force in the lubrication system, which is essential for achieving macroscale superlubricity over a long time. This study provides a new perspective for designing robust superlubricity systems by harnessing the tribocatalytic effect of high‐entropy materials.