Open and closed microfluidics for biosensing.

Biosensing is vital for many areas like disease diagnosis, infectious disease prevention, and point-of-care monitoring. Microfluidics has been evidenced to be a powerful tool for biosensing via integrating biological detection processes into a palm-size chip. Based on the chip structure, microfluidics has two subdivision types: open microfluidics and closed microfluidics, whose operation methods would be diverse. In this review, we summarize fundamentals, liquid control methods, and applications of open and closed microfluidics separately, point out the bottlenecks, and propose potential directions of microfluidics-based biosensing.

Identification of hydrochemical fingerprints, quality and formation dynamics of groundwater in western high Himalayas.

Identifying hydrochemical fingerprints of groundwater is a challenge in areas with complex geological settings. This study takes the Gilgit-Baltistan, a complex geological area in west high Himalayas, Pakistan, as the study area to get insights into the hydrochemcial genesis and quality of groundwater in complex geological mountainous regions. A total of 53 samples were collected across the area to determine the hydrochemical characteristics and formation of groundwater. Results revealed groundwater there is characterized by slightly alkaline and soft fresh feature. Groundwater is dominated by the hydrochemical facies of HCO3·SO4-Ca·Mg type. The factor method yields three components (PCs) of principal component analysis, which together explain 75.71% of the total variances. The positive correlation of EC, TDS, Ca2+, SO42-, K+ in PC1, and NO3-, Cl- in PC2 indicate that a combination of natural and anthropogenic activities influences groundwater hydrochemistry. Water-rock interaction is the main mechanism governing the natural hydrochemistry of groundwater. The negative correlation of Cl-, SO42-, Ca2+, and Na+ with NDVI attributes to inorganic salt uptake by plant roots. Groundwater chemical composition is also affected by the type of land use. Groundwater is characterized as excellent and good water quality based on the entropy-weighted water quality index assessment, and is suitable for drinking purposes except for very few samples, while aqueous fluoride would pose potential health threats to water consumers in western high Himalayas, and infants are most at risk compared to other populations. This study will help to deepen the hydrochemial formation mechanism and exploitation suitability of groundwater resources in the mountainous areas that undergone the combined actions of nature and human activities, and provide insights into the characteristics of water environmental quality in western Himalayas area.

Ginsenoside Rg1 attenuates liver injury induced by D-galactose in mice.

The present study investigated the effect and underlying mechanisms of ginsenoside Rg1 (Rg1) in attenuating subacute liver injury induced by D-galactose (D-gal) in mice. Specific Pathogen Free (SPF) male C57BL/6J mice were randomly divided into 3 groups: i) D-gal-administration group (D-gal group), where the mice were intraperitoneally administrated with D-gal (120 mg/kg/day for 42 days); ii) D-gal + Rg1 group where the mice were treated with 120 mg/kg/day D-gal for 42 days and with Rg1 at a dose of 20 mg/kg/day for 35 days. The first dose of Rg1 was administered on the 8th day of treatment with D-gal; and iii) the normal control group, where the mice were injected with an equal volume of saline for 42 days. The day following the final injections in all groups, peripheral blood was collected and serum was prepared to measure the contents of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBiL), advanced glycation end products (AGEs) and 8-hydroxy-2 deoxyguanosine (8-OH-dG). Liver tissue homogenates were prepared to measure the contents of malondialdehyde (MDA) and glutathione (GSH), and the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). Paraffin section were prepared to observe the microscopic structure of the liver. Transmission electron microscopy was used to observe the ultrastructure of hepatocytes. Frozen section were prepared and stained with senescence-associated ß-galactosidase to detect the relative optical density value of senescence-associated markers. Compared with the D-gal group, the contents of AST, ALT, TBiL, AGEs and MDA significantly decreased in the D-gal + Rg1 group, while the activities of SOD and GSH-Px markedly increased, and liver injury and degenerative alterations of hepatocytes were reduced. Administration of Rg1 induced a protective effect on D-gal-induced liver injury in mice by inhibiting the oxidative stress, reducing DNA damage and decreasing the AGE content.

The regulation of ginsenoside Rg1 upon aging of bone marrow stromal cell contribute to delaying senescence of bone marrow mononuclear cells (BMNCs).

To investigate the effect and mechanism of ginsenoside Rg1 antagonizing bone marrow stromal cells (BMSCs) aging, which contribute to the delaying senescence of hematopoietic cells in vitro and in vivo. Rg1 could reduce the effects of senility agent on BMSCs by decreasing the rate of SA-Gal positive cells, and increasing the proliferative ability of CCK8 cells. After BMNCs co-cultured with BMSCs which were treated by Rg1 in vitro, compared with BMNCs co-cultured with BMSCs from aging group, percentage of positive cell SA-Gal staining was decreased, the formation ability of CFU-Mix was enhanced, the proliferative ability was increased, and the apoptosis rate was decreased. In aging rat model, after treated with Rg1, the percentage of positive cell SA-Gal staining in BMSCs was significantly decreased, the proliferative ability was increased. After treated with Rg1, the percentage of positive cell SA-Gal staining in BMNCs was significantly decreased, the formation ability of CFU-Mix mixed colony was enhanced, ROS was decreased, and SOD activity was increased. Aging BMSCs could induce the senescence of BMNCs. Rg1 could antagonize the effect of d-gal on the aging of BMSCs both in vivo and in vitro, and restore the hematopoietic capacity of BMNCs through the different pathways.

Enhancement of backward second harmonic generation of acoustic waves in a resonant cavity by using a superlattice.

In this paper, the enhancement effect of backward second harmonic generation of acoustic waves in the system, consisting of a linear solid superlattice and a nonlinear liquid resonant cavity, is investigated analytically and numerically. Results show the nonlinear effect in the system can be enhanced drastically due to the existence of defective modes and the large acoustic impedance mismatching between solids and liquids. Because of the latter, the dual-resonance phenomenon can always take place approximately and automatically. These results are different from previous conclusions in optical fields.

The positive effects of Ginsenoside Rg1 upon the hematopoietic microenvironment in a D-Galactose-induced aged rat model.

BACKGROUND: Ginsenoside Rg1 (Rg1) is one of the most active ingredients in Panax ginseng and has been proven to have anti-oxidative and anti-aging properties. However, there have been few reports concerning the anti-aging effects of Rg1 on the hematopoietic microenvironment and bone marrow stromal cells (BMSCs). METHODS: Thirty Sprague-Dawley rats were randomly divided into four groups (control, D-galactose (D-gal)-administration, Rg1-treatment, and D-gal-administration + Rg1-treatment groups). After D-gal and Rg1 treatment, BMSCs were extracted from femoral bone marrow for culture. After three passages, BMSCs were tested by senescence-associated ß-galactosidase (SA-ß-gal) staining, flow cytometric cell cycle phase distribution assay, CCK-8 cell proliferation assay, oxidative stress (reactive oxygen species [ROS], superoxide dismutase [SOD], and malondialdehyde [MDA]) assays, inflammatory marker (interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α) enzyme-linked immunosorbent assay (ELISA), stem cell factor (SCF) ELISA, and senescence-associated protein (p16, p21, and p53) Western blotting. RESULTS: Compared to the D-gal-administration group, the D-gal-administration + Rg1-treatment group showed significantly decreased levels of SA-ß-gal + cell %, ROS, MDA, inflammatory marker expression, and senescence-associated protein expression as well as significantly increased levels of S-phase %, cell proliferation, SOD activity, and SCF expression. Compared to controls, the Rg-1-treatment group displayed significantly reduced levels of SA-ß-gal + cell %, G1 phase %, ROS, MDA, inflammatory marker expression, senescence-associated protein expression, and SCF expression as well as significantly increased levels of S-phase %, cell proliferation, and SOD activity. CONCLUSIONS: Rg1 improves the anti-aging ability of hematopoietic microenvironment through enhancing the anti-oxidant and anti-inflammatory capacities of BMSCs.

Investigations of the barbell ultrasonic transducer operated in the full-wave vibrational mode.

In this paper, the resonance frequency equation and expression of displacement amplitude magnifications of a full-wave barber ultrasonic horn are obtained. By discussing the relationships between the displacement amplitude magnifications and the geometrical dimensions, the optimized design of the horn for the largest magnification is proposed, which is helpful to improve the radiation power and the transfer efficiency of the acoustic energy of the ultrasonic oscillatory system. Based on the optimized design of the horn, we introduced a barbell ultrasonic transducer operated in the longitudinal full-wave vibrational model and obtained the resonance frequency equations. For comparison, the resonance frequencies of the full-wave barbell horn and the full-wave barbell transducer are also analyzed by finite element method (FEM). It is shown that the values obtained by theoretical analysis and FEM are in good agreement with experimental observations. We hope that the research of this paper is helpful for the use of the barbell horn and transducer in the applications such as ultrasonic liquid processing.

Optimization design of high power ultrasonic circular ring radiator in coupled vibration.

This paper presents a new high power ultrasonic (HPU) radiator, which consists of a transducer, an ultrasonic horn, and a metal circular ring. Both the transducer and horn in longitudinal vibrations are used to drive a metal circular ring in a radial-axial coupled vibration. This coupled vibration cannot only generate ultrasound in both the radial and axial directions, but also focus the ultrasound inside the circular ring. Except for the radial-axial coupled vibration mode, the third longitudinal harmonic vibration mode with relative large vibration amplitude is also detected, which can be used as another operation mode. Overall, the HPU with these two vibration modes should have good potential to be applied in liquid processing, such as sonochemistry, ultrasonic cleaning, and Chinese herbal medicine extraction.

[Distraction osteogenesis in correcting facial asymmetry malformation caused by temporomandibular joint ankylosis: a case report].

A facial asymmetry patient caused by temporomandibular joint ankylosis was operated by putting a distraction osteogenesis (DO)-appliance. One week after surgery, the right mandible was distracted. Twenty days after distraction, the height of right mandibular ramus and body increased obviously. Four months after retain of DO-appliance, the right maxilla down-grew automatically and the occluding relation recovered to normal. The DO-appliance was taken out. MEDPOR prosthesis was imbedded in new bone and genioplasty was operated. The facial asymmetry and abnormal occluding relation of the patient were improved obviously.