Nano-optical method for transforming a single yeast cell using exogenous genes.

We report a highly efficient nano-optical method for transforming a single yeast cell using exogenous genes. It used laser tweezers or micromanipulators to immobilize the cell immersed in a DNA solution and created a transient nano-sized hole on its cell wall concurrently with laser scissors to deliver nano moles of DNA into the cell. With this method, one can directly transfer the naked DNA of exogenous genes into yeast cells for transformation.

AI Aided Analysis on Saliva Crystallization of Pregnant Women for Accurate Estimation of Delivery Date and Fetal Status.

Saliva contains similar molecular components to serum. Analysis of saliva can provide important diagnostic information about the body. Here we report an artificial intelligence (AI) aided home-based method that can let pregnant women perform daily monitoring on their pregnant status and accurate prediction on their delivery date by the pattern analysis of their salivary crystals.

Effects of Low-Dose X-Ray on Cell Growth, Membrane Permeability, DNA Damage and Gene Transfer Efficiency.

Background: We aimed to reveal if low dose X-rays would induce harmful or beneficial effect or dual response on biological cells and whether there are conditions the radiation can enhance gene transfer efficiency and promote cell growth but without damage to the cells.

Method: A systematic study was performed on the effects of Kilo-V and Mega-V X-rays on the cell morphology, viability, membrane permeability, DNA damage, and gene transfection of 293 T and CHO cells.

Results: The Kilo-V X-rays of very low doses from 0.

A Smart Phone Based Handheld Wireless Spirometer with Functions and Precision Comparable to Laboratory Spirometers.

We report a smart phone based handheld wireless spirometer which uses a Lilly type sensing flowhead for respiratory signal acquisition and transmits the data to smartphone or other mobile terminals with Bluetooth signal transmission for data processing and result display. The developed spirometer was demonstrated to be able to detect flow rates ranging from 0-15 L/s with an accuracy of 4 mL/s, and can perform tests of flow volume (FV), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), etc. By having the functions and precision comparable to laboratory spirometers, it satisfies the American Thoracic Society and European Respiratory Society (ATS/ERS) proposed performance requirements for spirometer.

Technique of laser chromosome welding for chromosome repair and artificial chromosome creation.

Here we report a technique of laser chromosome welding that uses a violet pulse laser micro-beam for welding. The technique can integrate any size of a desired chromosome fragment into recipient chromosomes by combining with other techniques of laser chromosome manipulation such as chromosome cutting, moving, and stretching. We demonstrated that our method could perform chromosomal modifications with high precision, speed and ease of use in the absence of restriction enzymes, DNA ligases and DNA polymerases.

Versatile on-stage microfluidic system for long term cell culture, micromanipulation and time lapse assays.

We report here a versatile on-stage microfluidic cell culture and assay system which is compatible with different microscopes and sensors, can simultaneously perform steps of long term cell culture, high throughput time lapse cell assays/imaging, and cell micromanipulations. With the system, we cultured a variety of cells for different periods of time and monitored their cell morphology, migration and division. We also performed a series non-invasive real time in situ time lapse assays and micromanipulations on different cells.

Easy and rapid multi-pass detection of antigen and antibody with micro-lens sensors.

We introduce a micro-lens imaging method that can perform easy and rapid multi-pass detection of antigen/antibody (Ag/Ab) without the requirement of any labeling, expensive enzymes, pre-immobilization/modification, and post-washing. Our method detects Ag or Ab presenting in solutions in a quantitative or qualitative manner by using micro-lens as the sensor to monitor the refractive index variation of the solutions during the primary stage of Ag-Ab reaction. The detection can be taken rapidly and finished in two minutes, while requires very low sample volume (several micron liters) and its detection limit can be as low as ∼pg/mL.

Simultaneous Determination of Glass Transition Temperatures of Several Polymers.

Aims: A simple and easy optical method is proposed for the determination of glass transition temperature (Tg) of polymers.

Methods & Results: Tg was determined using the technique of microsphere imaging to monitor the variation of the refractive index of polymer microsphere as a function of temperature. It was demonstrated that the method can eliminate most thermal lag and has sensitivity about six fold higher than the conventional method in Tg determination.

Restoring the youth of aged red blood cells and extending their lifespan in circulation by remodelling membrane sialic acid.

Membrane sialic acid (SA) plays an important role in the survival of red blood cells (RBCs), the age-related reduction in SA content negatively impacts both the structure and function of these cells. We have therefore suggested that remodelling the SA in the membrane of aged cells would help recover cellular functions characteristic of young RBCs. We developed an effective method for the re-sialylation of aged RBCs by which the cells were incubated with SA in the presence of cytidine triphosphate (CTP) and α-2,3-sialytransferase.

How cell number and cellular properties of blood-banked red blood cells of different cell ages decline during storage.

Aims: Numerous studies have suggested that transfusion of red blood cells (RBCs) stored over a long period of time may induce harmful effects due to storage-induced lesions. However, the underlying mechanisms responsible for this damage have not been identified. Furthermore, it is unclear why and how up to 30% of long-stored RBCs disappear from the circulation within 24 hours after transfusion.

[Surface-enhanced Raman spectra analysis of trace degradation products from goat horn].

Nano-silver colloid was synthesized by using microwave method on the mixtures of sodium citrate solution and silver nitrate solution. The method has advantages of fast heating speed, uniform temperature distribution and easily controlled reaction conditions. The sizes and size distributions of the silver particles were characterized by means of quasi-elastic laser scattering (QLS).

KrF excimer laser precision machining of hard and brittle ceramic biomaterials.

KrF excimer laser precision machining of porous hard-brittle ceramic biomaterials was studied to find a suitable way of machining the materials into various desired shapes and sizes without distorting their intrinsic structure and porosity. Calcium phosphate glass ceramics (CPGs) and hydroxyapatite (HA) were chosen for the study. It was found that KrF excimer laser can cut both CPGs and HA with high efficiency and precision.

Pathway and mechanism of pH dependent human hemoglobin tetramer-dimer-monomer dissociations.

Hemoglobin dissociation is of great interest in protein process and clinical medicine as well as in artificial blood research. However, the pathway and mechanisms of pH-dependent human Hb dissociation are not clear, whether Hb would really dissociate into monomers is still a question. Therefore, we have conducted a multi-technique investigation on the structure and function of human Hb versus pH.

Microstructure and mechanical properties of horns derived from three domestic bovines.

The microstructure and mechanical properties of horns derived from three domestic bovines (buffalo, cattle and sheep) were examined. The effects of water content, sampling position and orientation of three bovid horns on mechanical properties were systematically investigated by uniaxial tension and micron indentation tests. Meanwhile, the material composition and metal element contents were determined by Raman spectroscopy and elemental analysis respectively, and the microstructures of the horns were measured by scanning electron microscopy (SEM).

Characteristic variation of α-fetoprotein DNA nanometer-range irradiated by iodine-125.

To obtain the characteristic variation of structure and functional groups of α-fetoprotein (AFP) DNA irradiated by iodine-125((125)I), the AFP antisense oligonucleotide labeled with various radioactivity dose (125)I was mixed with the AFP DNA in a simulated polymerase chain reaction temperature condition. After the mixtures were irradiated by the (125)I from 2 to 72 hours, the mutation of the biogenic conformation and functional groups of the irradiated DNA were investigated using laser Raman spectroscopy. The shifted peak and the decreased intensity of the characteristic Raman spectra were found, which demonstrated that the structure of the phosphodiester linkage was broke, the pyridine and purine bases in DNA emerged and damaged.

Micro optical power meter for direct in situ measurement of light transmitted from microscopic systems and focused on micro-samples.

This paper reports a micro optical power meter which is able to perform effective and precise measurement on the optical power at the focus of different microscopic systems. The power meter can be easily placed on the stages of different microscopes and even partly immersed into solution to directly measure the optical power transmitted from the microscope objective and focused on the sample suspended in solution. The testing experiments demonstrated that the power meter has the characteristics of high precision, excellent linearity, high sensitivity, good stability, and high responding speed.

Reactive oxygen species formation and apoptosis in human peripheral blood mononuclear cell induced by 900 MHz mobile phone radiation.

We demonstrate that reactive oxygen species (ROS) plays an important role in the process of apoptosis in human peripheral blood mononuclear cell (PBMC) which is induced by the radiation of 900 MHz radiofrequency electromagnetic field (RFEMF) at a specific absorption rate (SAR) of ~0.4 W/kg when the exposure lasts longer than two hours. The apoptosis is induced through the mitochondrial pathway and mediated by activating ROS and caspase-3, and decreasing the mitochondrial potential.

Easy method to determine refractive indices of microspheres and in micro-regions of inhomogeneous media.

We describe an innovative method which can accurately determine the refractive index (RI) of individual microspheres by immersing the microspheres in a medium and analyzing their phase-contrast microscopic images. Compared with the current techniques for microsphere RI measurement, the method has several advantages: it is simple and easy and it cannot only measure the RI of each individual microsphere but also perform measurement simultaneously on all the microspheres in the same field of view. In measurement, microspheres are not required to be suspended in a specific liquid but in any medium with known RI which is appropriate for the microspheres or even just in atmosphere.

[Qualitative analysis of Raman spectra based on pulse coupled neural network].

By studying on pulse coupled neural network (PCNN) and Raman spectra qualitative analysis, a method based on PCNN for Raman spectra qualitative analysis was proposed. After encoding the Raman spectra by using PCNN neurons' characteristics of fatigue and refractory period, the improved Horspool algorithm was used to match the code corresponding to the detected sample with all of the base code in the database one by one, and then their matching similarity was acquired to determine the sample type. Experimental results and analysis of data proved that the method proposed in this paper is accurate and effective for Raman spectra qualitative analysis.

[Raman spectra quantitative analysis on materials with strong fluorescence background].

Aiming at the difficulty of Raman spectra quantitative analysis on materials with strong fluorescence background, together with baseline correction, a new normalization method was performed for concentration quantitative analysis of two kinds of solutions which exhibit strong fluorescence background, the methanol solutions with different concentrations and the mixed solutions of ethanol and methanol with different ratios of concentration. Meanwhile, the data fluctuation caused by collecting spectra data at different space-time was investigated by using statistical method of randomized blocks analysis of variance to evaluate the data fluctuation among different sample groups, and the function of our method proposed in this paper to eliminate this data fluctuation was discussed. Experimental results demonstrate that our proposed method can not only obtain satisfied accuracy for Raman spectra quantitative analysis on methanol with strong fluorescence background, with the mean relative error being 4.

[Normalization methods for ethanol Raman spectra quantitative analysis].

By performing different Raman normalization methods for ethanol quantitative analysis, the authors proposed the method which used the highest band intensity of the ethanol Raman spectra in the maximum concentration as the normalization metric for ethanol concentration quantitative analysis. By using this method, the correlation coefficient was 0.999, the mean relative error was only 0.

Effect of pH on molecular constitution and distribution of hemoglobin in living erythrocyte.

The molecular constitution of in situ hemoglobin (Hb) and their distribution in living erythrocyte were investigated versus pH using the technique of confocal Raman microscopy. Both Raman point spectra and line mapping measurements were performed on living erythrocytes in suspensions with pH values from 4.82 to 9.