Gelation of liposome interior. A novel method for drug encapsulation.

Liposomes can be loaded with weak acids and bases, which exist in solutions in equilibrium with membrane permeable uncharged form, using various gradients across their membranes. Because in some cases the estimated drug concentration in the loaded liposomes exceeds their aqueous solubility we investigated the physical state of the liposome encapsulated anticancer drug Doxorubicin. X-Ray diffraction, electron microscopy, and test tube solubility experiments have shown that upon encapsulation the drug molecules form a gel-like phase.     

发酵戊糖产酒精酵母菌株的选育

介绍了一种新的发酵戊糖产酒酵母菌种筛选方法并利用该方法筛选出一株性能优良的发酵戊糖酵母蓖株Z8,该菌株性能测试结果为：产酒精能力相当于发酵戊糖理论产量的60．0％,耐酒精能力14％（V／V）,在温度高达42℃的条件下仍能正常发酵,初步鉴定该菌株为管囊酵母（Pachysolen tannophilus)。     

A rapid screening method to detect ethanol production by microorganisms

A method for detecting ethanol production by microorganisms on an agar plate is described. The assay is based on the enzymatic determination of ethanol. Yellow zones surround ethanol-producing colonies on a blue background and their diameter is an indication of the amount of ethanol produced.     

A novel method for encapsulation of macromolecules in liposomes

Hemoglobin and alkaline phosphatase were each encapsulated in phosphatidylcholine liposomes using a dehydration-rehydration cycle for liposome formation. In this method, liposomes prepared by sonication are mixed in aqueous solution with the solute desired to be encapsulated and the mixture is dried under nitrogen in a rotating flask. As the sample is dehydrated, the liposomes fuse to form a multilamellar film that effectively sandwiches the solute molecules. Upon rehydration, large liposomes are produced which have encapsulated a significant fraction of the solute. The optimal mass ratio of lipid to solute is approx. 1:2 to 1:3. This method has potential application in large-scale liposome production, since it depends only on a controlled drying and rehydration process, and does not require extensive use of organic solvents, detergents, or dialysis systems.     

A novel screening method to assess developability of antibody-like molecules

Monoclonal antibodies and antibody-like molecules represent a fast-growing class of bio-therapeutics that has rapidly transformed patient care in a variety of disease indications. The discovery of antibodies that bind to particular targets with high affinity is now a routine exercise and a variety of in vitro and in vivo techniques are available for this purpose. However, it is still challenging to identify antibodies that, in addition to having the desired biological effect, also express well, remain soluble at different pH levels, remain stable at high concentrations, can withstand high shear stress, and have minimal non-specific interactions. Many promising antibody programs have ultimately failed in development due to the problems associated with one of these factors. Here, we present a simple high-performance liquid chromatography (HPLC)-based screening method to assess these developability factors earlier in discovery process. This method is robust and requires only microgram quantities of proteins. Briefly, we show that for antibodies injected on a commercially available pre-packed Zenix HPLC column, the retention times are inversely related to their colloidal stability with antibodies prone to precipitation or aggregation retained longer on the column with broader peaks. By simply varying the salt content of running buffer, we were also able to estimate the nature of interactions between the antibodies and the column. We believe this approach should generally be applicable to assessment of the developability of other classes of bio-therapeutic molecules, and that the addition of this simple tool early in the discovery process will lead to selection of molecules with improved developability characteristics.     

A novel screening method of cellulase-producing bacteria

Cellulase is the key to utilize the renewable and abundant cellulose resource, cellulase-producing microorganism is an important source of cellulase. The traditional screening method of cellulase-producing microorganism is low efficacy and not macroscopic. The screening method in this study was based on the interactive culture character between cellulase-producing bacteria and Phytophthora parasitica var. nicotianae on plates, the results indicated that the inhibition zone and cellulase activity of bacterial strains are conformity on the whole, so the screening method is very quickly and apparent.     

A novel method to produce armored double-stranded DNA by encapsulation of MS2 viral capsids

With the rapid development of molecular diagnostic techniques, there is a growing need for quality controls and standards with favorable properties to monitor the entire detection process. In this study, we describe a novel method to produce armored hepatitis B virus (HBV) and human papillomavirus (HPV) DNA for use in nucleic acid tests, which was confirmed to be stable, homogeneous, noninfectious, nuclease resistant, and safe for shipping. We demonstrated that MS2 bacteriophage could successfully package double-stranded DNA of 1.3-, 3-, 3.5-, and 6.5-kb length into viral capsids with high reassembly efficiency. This is the first application of RNA bacteriophage MS2 as a platform to encapsulate double-stranded DNA, forming virus-like particles (VLPs) which were indistinguishable from native MS2 capsids in size and morphology. Moreover, by analyzing the interaction mechanism of pac site and the MS2 coat protein (CP), we found that in addition to the recognized initiation signal TR-RNA, TR-DNA can also trigger spontaneous reassembly of CP dimers, providing a more convenient and feasible method of assembly. In conclusion, this straightforward and reliable manufacturing approach makes armored DNA an ideal control and standard for use in clinical laboratory tests and diagnostics, possessing prospects for broad application, especially providing a new platform for the production of quality controls for DNA viruses.     

An novel immobilization method of Saccharomyces cerevisiae to sorghum bagasse for ethanol production

Natural sorghum bagasse without any treatment was used to immobilize Saccharomyces cerevisiae at 0.6+/-0.2g dry cell weight (DCW)/g dry sorghum bagasse weight (DSW) through solid-state or semi-solid state incubation. The scanning electron microscopy (SEM) of the carriers revealed the friendship between yeast cells and sorghum bagasse are adsorption and embedding. The ethanol productivity of the immobilized cells was 2.24 times higher than the free cells. In repeated batch fermentation with an initial sugar concentration of 200g/L, nearly 100% total sugar was consumed after 16 h. The ethanol yield and productivity were 4.9 g/g consumed sugar on average and 5.72 g/(Lh), respectively. The immobilized cell reactor was operated over a period of 20 days without breakage of the carriers, while the free cell concentration in the effluent remained less than 5 g/L thoughout the fermentation. The maximum ethanol productivity of 16.68 g/(Lh) appeared at the dilution rate of 0.3h(-1).     

A novel non-invasive optical method for quantitative visualization of pH dynamics in the rhizosphere of plants

A novel optical method for non-invasive, quantitative and high-resolution imaging of spatial and temporal pH dynamics in soils mediated by plant roots is introduced. This method overcomes present limitations of measurement of pH, mainly short-term and punctiform measurements, by recording long-term dynamics of the micro-pattern of pH in the root-soil interface without disturbance of the biological and physico-chemical conditions. Juncus effusus L., rooting in a permanently flooded rhizotron, was selected as the test organism for qualifying the technique. The measurements showed pronounced diurnal variations of pH along the roots, particularly along the elongation zone. Diurnal oscillation of pH caused by the roots reached up to 0.5 units. Long-term records at 4 s intervals over more than 8 weeks revealed considerable spatial and temporal patterns of pH dynamics in the rhizosphere of about 10% of the pH scale (pH 7.0-8.5). The measured data were validated by the use of pH electrodes. Concomitantly measured oxygen concentration showed hypoxic conditions around root tips (10-70 micromol O2 L-1) and almost anoxic conditions (0.9 micromol O2 L-1) in the bulk soil. The present study qualifies this novel pH-sensing technique as a powerful analytical tool for quantitative visualization of undisturbed bioprocess dynamics.     

一种便携式测定昆虫过冷却点的方法

本文介绍了热敏电阻 +万用电表测定昆虫过冷却点的新方法。通过实验比较发现使用热敏电阻法测定昆虫过冷却点较之热电偶法有如下优点 :(1)测量灵敏度和精确度高 ;(2 )测定昆虫范围广 ;(3)装置体积小 ,不用交流电 ,携带方便 ;(4 )价格较低。     

A novel method of screening thrombin-inhibiting DNA aptamers using an evolution-mimicking algorithm

Thrombin-inhibiting DNA aptamers have already been obtained through the systematic evolution of ligands by exponential enrichment (SELEX). However, SELEX is a method that screens DNA aptamers that bind to their target molecules, and it sometimes fails to screen good inhibitors. Therefore, it is necessary to develop a method of screening DNA aptamers based on their inhibitory effects on the target molecules. We developed a novel method of detecting aptamers using an evolution-mimicking algorithm, and we applied it to the search of new aptamers which inhibit thrombin. First, we randomly designed and synthesized ten 15mer oligonucleotides presumed to form G-quartet structures, and then measured their thrombin-inhibiting activities. The aptamers showing high inhibitory activity were selected, and we shuffled and mutated those sequences in silico to generate 10 new sequences of next-generation aptamers. After repeating the cycle five times, we successfully obtained the same aptamers reported previously, and they showed high inhibitory activity. In addition, we added 8mer oligonucleotides to both the 5′ and the 3′ end of the selected 15mer aptamers, and then repeated the evolution in silico. After two cycles, we were able to obtain aptamers with higher inhibitory activity than that of the 15mer aptamers.     

A novel method for non-invasive detection of aflatoxin contaminated dried figs with deep transfer learning approach

Aflatoxins are the most dangerous mycotoxin produced by Aspergillus fungal species, such as Aspergillus flavus and Aspergillus parasiticus, and can cause various health problems, including liver cancer, in humans. Figs and many agricultural products are affected by aflatoxins. It is crucial to detect it before consumption since it is impossible to clean aflatoxin from contaminated foods. Chromatographic methods are considered the gold standard for aflatoxin detection, but these methods are pretty expensive, time-consuming, and destructive. Therefore, various studies have been conducted on non-invasive aflatoxin detection using optical spectroscopic methods. Specifically, aflatoxin-contaminated figs are sorted manually by employees in production facilities using the Bright Greenish Yellow Fluorescence (BGYF) method under ultraviolet (UV) light. However, accurate and safe manual sorting depends on expertise of employees, along with this long exposure time to UV radiation may cause employees skin cancer and eye disorders. This study presents a deep transfer learning-based approach for non-invasive detection and classification of aflatoxin-contaminated dried figs using images captured under UV light. Pre-trained transfer learning models, such as DenseNet, ResNet, VGG, and InceptionNet, are applied to the dataset, but the accuracy of these models does not outperform the other methods that detect aflatoxin with the BGYF method. Therefore, fine-tuning is performed on the models. As a result, training accuracy of 98.57% and validation accuracy of 97.50% is obtained using the DenseNet169 model. The experimental results show that our proposed method achieves the highest accuracy among other methods. Also, the proposed method shows that deep CNN can be used to automatically, rapidly, and effectively detect aflatoxin-contaminated figs.     

A simplified screening test for the diagnosis of allergy.

The Quidel allergy screen is a relatively rapid (less than 2 hours) multiallergen dipstick method for detecting specific immunoglobin E antibodies in serum. It was developed to answer the need of primary physician nonspecialists in allergy for a convenient in-office screening test for diagnosing allergy. The new test was evaluated against the benchmark diagnostic skin tests and the radioallergosorbent serologic tests for sensitivity, specificity, accuracy, and technical feasibility in an office setting. It was found that while the Quidel allergy screen lacks the specificity of the standard tests, its overall sensitivity, as defined by the percentage of patients with positive skin reactions who also tested positive with the Quidel screen (68%), its ease of use, and its rapidity warrant its consideration as a screening tool for confirming a possible case of allergy.     

A novel method to separate the layers of the intestine.

By applying cellulose acetate paper to the lumenal and serosal surface of the intestine of rats, we have divided the intestine into three layers. Examining the layers histologically, we have shown that most of the villi are removed from the mucosal surface, ther serosa alone is removed from the serosal surface, and muscle layers. This appears to provide a rapid procedure for separation of the layers of the intestine for histological and biochemical studies.     

A novel video-based method using projected light to measure trunk volumes during respiration

This paper proposes and evaluates an innovative video-based method for measuring the trunk volume during respiration, using projected light and surface reconstruction. The method consists of the following main steps: (a) to project a grid of circular light markers on the anterior and posterior human body trunk surface during breathing, (b) to register the subject's trunk surface using two pairs of pre-calibrated digital video cameras, (c) to segment the video stream and track the projected markers using pre-processing techniques, morphological operators and detection algorithms, (d) to label the corresponding markers in the video sequences registered by each pair of stereo cameras, (e) to reconstruct the 3-D coordinates of all markers, (f) to reconstruct the surfaces from the unordered cloud of points using the Power Crust method and (g) to calculate the trunk volume in function of time using the divergence theorem. The evaluation of the method was based on two experiments. (1) Comparison of the volume of a trunk model (mannequin) by immersion and using the proposed optical method. (2) Analysis of the applicability of the method for measuring a subject’s trunk volume during a vital capacity respiratory manoeuvre. The results showed that the method was able to automatically measure more than 2000 projected points per image and to provide a very detailed representation of the subject's trunk. The relative accuracy of the volume measurement was estimated to be better than 3%. The analysis of the experiments revealed that signals coherent with the respiratory cycles could be identified through this method. In conclusion, the method based on light projection and surface reconstruction provides an accurate, non-invasive and useful means to calculate human trunk volumes during breathing.     

A novel video-based method using projected light to measure trunk volumes during respiration

This paper proposes and evaluates an innovative video-based method for measuring the trunk volume during respiration, using projected light and surface reconstruction. The method consists of the following main steps: (a) to project a grid of circular light markers on the anterior and posterior human body trunk surface during breathing, (b) to register the subject's trunk surface using two pairs of pre-calibrated digital video cameras, (c) to segment the video stream and track the projected markers using pre-processing techniques, morphological operators and detection algorithms, (d) to label the corresponding markers in the video sequences registered by each pair of stereo cameras, (e) to reconstruct the 3-D coordinates of all markers, (f) to reconstruct the surfaces from the unordered cloud of points using the Power Crust method and (g) to calculate the trunk volume in function of time using the divergence theorem. The evaluation of the method was based on two experiments. (1) Comparison of the volume of a trunk model (mannequin) by immersion and using the proposed optical method. (2) Analysis of the applicability of the method for measuring a subject's trunk volume during a vital capacity respiratory manoeuvre. The results showed that the method was able to automatically measure more than 2000 projected points per image and to provide a very detailed representation of the subject's trunk. The relative accuracy of the volume measurement was estimated to be better than 3%. The analysis of the experiments revealed that signals coherent with the respiratory cycles could be identified through this method. In conclusion, the method based on light projection and surface reconstruction provides an accurate, non-invasive and useful means to calculate human trunk volumes during breathing.