Small biomolecules play a critical role in the fundamental processes that sustain life and are essential for the proper functioning of the human body. The detection of small biomolecules has garnered significant interest in various fields, including disease diagnosis and medicine. Electrochemical techniques are commonly employed in the detection of critical biomolecules through the principle of redox reactions. It is also a very convenient, cheap, simple, fast, and accurate measurement method in analytical chemistry. Zeolitic imidazolate frameworks (ZIFs) are a unique type of metal-organic framework (MOF) composed of porous crystals with extended three-dimensional structures. These frameworks are made up of metal ions and imidazolate linkers, which form a highly porous and stable structure. In addition to their many advantages in other applications, ZIFs have emerged as promising candidates for electrochemical sensors. Their large surface area, pore diameter, and stability make them ideal for use in sensing applications, particularly in the detection of small molecules and ions. This review summarizes the critical role of small biomolecules in the human body, the standard features of electrochemical analysis, and the utilization of various types of ZIF materials (including carbon composites, metal-based composites, ZIF polymer materials, and ZIF-derived materials) for the detection of important small biomolecules in human body fluids. Lastly, we provide an overview of the current status, challenges, and future outlook for research on ZIF materials.
Micro Electro Discharge Machining (micro-EDM) is widely used for producing different types of micro features and micro components. Tool wear rate (TWR) is an important factor that affects the accuracy of machining as well as the productivity of micro-EDM process. This study examines the effects of process parameters and the use of Maghemite (γ-Fe2O3) nano-powder mixed dielectric medium on tool wear rate when micro-EDM Co-Cr-Mo. A Copper electrode with 300 μm diameter and positive polarity was used to evaluate the machining process by focusing on TWR. Two different concentrations of nano-powder (i.e., 2 g/l and 4 g/l) were added to the dielectric. Results showed that increasing the discharge current and voltage leads to a corresponding increase in TWR, while the presence of γ-Fe2O3 nano-powder in the dielectric liquid decreases TWR. Mixed micro-EDM with 2 g/l of nano-powder achieved a lower TWR.
The carnivorous plants of genus Nepenthes produce unique pitchers containing secretory glands, which secrete proteins into the digestive fluid. We investigated protein profile in the pitcher fluid during the first three days of opening to understand carnivory trait of Nepenthes × ventrata. The proteome analysis of pitcher fluid from N. × ventrata was performed by label-free quantitative liquid chromatography mass spectrometry (nLC-MS/MSALL). Raw MS data have been deposited to the ProteomeXchange with identifier PXD007251. This dataset allows the identification and quantification of proteins from pitcher fluids to elucidate proteins involved in carnivory physiology of Nepenthes species.
The emission of Extreme Ultra Violet (EUV) from plasma produced by vacuum spark discharge using stainless steel as anode material was investigated. The operating pressure for all the experiments carried out was maintained at below 10-4 mbar. The discharge voltage tested was from 8 kV to 20 kV. The inter-electrode distance suitable for high intensity and reproducible EUV emissions was found to be in the range of 2.6 mm to 4.6 mm. The output EUV energy scaled as ~ V02, where V0 is the discharge voltage.
A number of relative permeability models were present in the literature, which were used to generate relative permeability data for the fluids, present in the porous medium. Some models were more significant to reservoir geology and displacement system (imbibitions and drainage system), while developing the correlations. Similarly, the same is kept in mind while performing reservoir studies. Therefore, in this study different models based on displacement system and formation geology have been compared, while including the effect of fluid saturation distribution/end point saturation in a reservoir. The generated relative permeability data by using these models have been further used to predict the reservoir performance for gas and water-displacement systems. The results based on this study showed that at lower saturations of displacing fluid (gas and/or water), the generated reservoir performance curves based on relative permeability data generated by using Corey and Wylie and Gardner models, gives higher degree of deviation on comparative basis. The behavior of these error or deviation curves for displacing phase is opposite in case of gas and water-oil displacement systems. While in case of displaced phase (oil), generally analogous behavior can be observed for both systems in terms of deviation/ error profiles trends. These reservoir performance curve(s) are of utmost significance in developing reservoir in an appropriate manner and a slight variation in relative permeability data can have a significant impact at macroscopic level.
A 50Hz glow discharge He/CH4
plasma was generated and applied for the glass surface modification to reduce the powder
adhesion on wall of spray dryer. The hydrophobicity of the samples determined by the water droplet contact angle and
adhesion weight on glass, dependent on the CH4 flow rate and plasma exposure time. The presence of CH3
groups and
higher surface roughness of the plasma treated glass were the factors for its hydrophobicity development. Response
surface methodology (RSM) results using central composite rotatable design (CCRD) showed that optimal responses
were obtained by the combination of parameters, CH4
gas flow rate = 3 sccm and exposure time = 10 min. In optimum
conditions, the contact angle increased by 47% and the weight of the adhesion reduced by 38% (w/w). The plasma
treatment could enhance the value of the contact angle and thus reduced the adhesion on the spray dryer glass surface.
Post-traumatic parotid sialocoele is a subcutaneous extravasation of saliva from the parotid gland secondary to traumatic disruption of its duct or parenchyma. Currently, there is no consensus regarding the best therapy for parotid sialocoele, as it is resistant to conservative management. The present paper puts forward a relatively simple, safe and effective technique for the treatment of parotid sialocoele, specifically a peroral drainage technique. The results justify our recommendation to use this approach for the treatment of sialocoele.
The main objective of the study was to correlate the target dry weight in haemodialysis (HD) patients as assessed clinically by nephrologists to those measured by the Body Composition Monitor (BCM - Fresenius) machine. The second objective was to compare pre and postdialysis changes of extracellular fluid and clinical parameters.
Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.
A three phase hollow fiber liquid-phase microextraction with in situ derivatization (in situ HF-LPME) followed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV) method was developed for the trace determination of metformin hydrochloride (MH) in biological fluids. A new derivatization agent pentafluorobenzoyl chloride (PFBC) was used. Several parameters that affect the derivatization and extraction efficiency were studied and optimized (i.e., type of organic solvent, volume of NaOH (4M) and derivatization agent in the donor phase, acceptor phase (HCl) concentration, stirring speed, temperature, time and salt addition). Under the optimum conditions (organic solvent, dihexyl ether; volume of NaOH (4M) and derivatization agent (10mg PFBC in 1mL acetonitrile) in the donor phase, 600 and100μL, respectively; acceptor phase, 100mM HCl (10μL); stirring speed, 300rpm; extraction time, 30min; derivatization temperature, 70°C; without addition of salt) an enrichment factor of 210-fold was achieved. Good linearity was observed over the range of 1-1000ngmL(-1) (r(2)=0.9998). The limits of detection and quantitation were 0.56 and 1.68ngmL(-1), respectively. The proposed method has been applied for the determination of MH in biological fluids (plasma and urine) and water samples. Prior to the microextraction treatment of plasma samples, deproteinization step using acetonitrile was conducted. The proposed method is simple, rapid, sensitive and suitable for the determination of MH in a variety of samples.
Ketidaksuburan idiopati dalam kalangan lelaki telah dikaitkan dengan kesan psikostres. Walaupun begitu, hubungan langsung antara psikostres dan ketaknormalan kualiti semen masih samar. Maka, kajian ini dijalankan untuk menentukan kesan psikostres terhadap kualiti semen terutama kesan berdasarkan residu sitoplasma dan kerosakan DNA sperma. Dalam kajian ini, responden lelaki berumur antara 25-45 tahun dipilih secara rawak dalam kalangan pesakit yang mendapatkan rawatan di Pusat Kesuburan Lembaga Penduduk dan Pembangunan Keluarga Negara (LPPKN). Seramai 331 responden akhirnya telah dipilih daripada 628 responden selepas mengambil kira faktor penolakan. Setiap responden perlu menjawab borang keizinan dan soal selidik GHQ-12 bagi penentuan tahap stres sebelum pengambilan sampel semen mengikut piawaian WHO (2010). Tahap stres diukur berdasarkan keadaan semasa responden dalam tempoh 3-4 minggu sebelum kajian. Analisis semen, pewarnaan papanicolau dan asai komet neutral digunakan untuk penentuan kualiti semen dan kerosakan DNA sperma. Keputusan menunjukkan tidak terdapat hubungan yang signifikan antara psikostres dan ketaknormalan residu sitoplasma (U=895.50, p=0.08). Namun begitu, psikostres memberi kesan kepada peratus morfologi normal (U=6317.50, p<0.05) dan kerosakan DNA sperma (U=1047.00, p<0.01). Kesimpulannya, psikostres kronik boleh menjejaskan kualiti semen dan kerosakan DNA sperma serta mempengaruhi kesuburan.
Nickel-titanium shape memory alloy (NiTi) has a unique capacity to restore its initial shape after deformation, which is highly applicable to orthopaedic implantations, especially for the minimization of invasive surgeries. The high nickel content of this alloy can lead to unfavourable effects on the human body upon dissolution; thus, a reliable barrier of coatings on the NiTi surface is required to alleviate the nickel migration and increase its biocompatibility. In this paper, analyses of a titanium oxide layer development on NiTi surface using electrical discharge coating (EDC) process is presented. The recast layer thickness, crater sizes, and surface roughness were characterized based on five parameters; polarity, discharge duration, pulse interval, peak current, and gap voltage. The results show that the discharge duration is the most significant parameter to influence all responses, followed by peak current. The surface characteristics of the EDC substrate is depending on the crater formations and is highly correlated with the discharge energy intensity. As a result, appropriate parametric conditions of the electrical discharge coating process can enhance the NiTi surface for future medical applications, without compromising the shape memory effect.
Telemetric EEG in the rat's brain has been used for experiments which tests the effects of an antiepileptic compound on it's antiseizures activity. A simple classification correlating epileptiform discharge and Racine's behavioral activity is discussed.
The discharge of electroplating waste containing nickel ions has led to environmental issues owing to the toxicity problem mainly to the aquatic organisms and humans. Liquid-liquid extraction offers a great potential treatment for nickel removal with several advantages of simple, high efficiency and high separation factor. In this study, a green synergistic liquid-liquid extraction of nickel ions from electroplating waste solution using chelating oxime (LIX63) and organophosphorus (D2EHPA) carriers individually as well as their synergistic mixture has been studied. The result demonstrated that about 83% of nickel ions have been successfully extracted via the mixture system of 0.08M LIX63 +0.02M D2EHPA with the maximum synergistic enhancement factor, Rmax of 29.56. Meanwhile, the back extraction study also revealed that HNO3 was the most suitable stripping agent while the diluent screening also showed that palm oil has high potential to be incorporated as a diluent in the green synergistic liquid-liquid extraction of nickel.
Satellite imagery reveals flowstripes on Foundation Ice Stream parallel to ice flow, and meandering features on the ice-shelf that cross-cut ice flow and are thought to be formed by water exiting a well-organised subglacial system. Here, ice-penetrating radar data show flow-parallel hard-bed landforms beneath the grounded ice, and channels incised upwards into the ice shelf beneath meandering surface channels. As the ice transitions to flotation, the ice shelf incorporates a corrugation resulting from the landforms. Radar reveals the presence of subglacial water alongside the landforms, indicating a well-organised drainage system in which water exits the ice sheet as a point source, mixes with cavity water and incises upwards into a corrugation peak, accentuating the corrugation downstream. Hard-bedded landforms influence both subglacial hydrology and ice-shelf structure and, as they are known to be widespread on formerly glaciated terrain, their influence on the ice-sheet-shelf transition could be more widespread than thought previously.
The aim of this study is to investigate the factors that cause landslides in the area along the new road between Cameron Highlands and Gua Musang. Landslide factors such as lineaments have been extracted from remote sensing data (Landsat TM image) using ERDAS software. A soil map has been produced using field work and laboratory analysis, and the lithology, roads, drainage pattern and rainfall have been digitized using ILWIS software together with the slope angle and elevation from the Digital Elevation Model (DEM). All these parameters, which are vital for landslide hazard assessment, have been integrated into the geographical information system (GIS) for further data processing. Weightage for these landslide relevant factors related to their influence in landslide occurrence using the heuristic method has been carried out. The results from this combination through a modified ‘index overlay with multi class maps’ model was used to produce a landslide hazard zonation map. Five classes of potential landslide hazard have been derived as the following: very low hazard zone 17.27%, low hazard zone 39.35%, medium hazard zone 25.1%, high hazard zone 15.35% and very high hazard zone 2.93%. The results from this work have been checked through the landslide inventory using available aerial photos interpretation and field work, and show that the slope and elevation have the most direct affect on landslide occurrence.