Identification of dipeptidyl peptidase-IV inhibitory peptides from mare whey protein hydrolysates.

Inhibition of dipeptidyl peptidase-IV (DPP-IV) activity is a promising strategy for treatment of type 2 diabetes. In the current study, DPP-IV inhibitory peptides were identified from mare whey protein hydrolysates obtained by papain. The results showed that all the mare whey protein hydrolysates obtained at various hydrolysis durations possessed more potent DPP-IV inhibitory activity compared with intact whey protein. The 4-h hydrolysates showed the greatest DPP-IV inhibitory activity with half-maximal inhibitory concentration of 0.18 mg/mL. The 2 novel peptides from 4-h hydrolysate fractions separated by successive chromatographic steps were characterized by liquid chromatography-electrospray ionization tandem mass spectrometry. The novel peptides Asn-Leu-Glu-Ile-Ile-Leu-Arg and Thr-Gln-Met-Val-Asp-Glu-Glu-Ile-Met-Glu-Lys-Phe-Arg, which corresponded to ß-lactoglobulin 1 f(71-77) and ß-lactoglobulin 1 f(143-155), demonstrated DPP-IV inhibitory activity with half-maximal inhibitory concentrations of 86.34 and 69.84 µM, respectively. The DPP-IV inhibitory activity of the 2 peptides was retained or even improved after simulated gastrointestinal digestion in vitro. Our findings indicate that mare whey protein-derived peptides may possess potential as functional food ingredients in the management of type 2 diabetes.

Effects of different anesthetic approaches on postoperative complications in HIV-infected patients.

The aim of this study was to investigate the effects of three different methods of anesthesia on patients with human immunodeficiency virus (HIV) infection, which could lead to an improvement in postoperative outcomes in these patients. A total of 90 patients undergoing an operation while being treated for an HIV infection were included in this study. Patients were divided into three groups (N = 30/group) based on the type of anesthesia administered: general anesthesia, local anesthesia, and combined spinal epidural anesthesia (CSEA). The effects of local infiltration of anesthesia and peripheral nerve block local anesthesia were examined in the local anesthesia group. The CSEA group examined the effects of spinal anesthesia in HIV-infected patients. We compared the vital signs of the three groups during the preoperative period, at incision, and during the postoperative recovery period. The CSEA group had a significantly higher mean preoperative CD4(+) T lymphocyte count compared with the general anesthesia and local anesthesia groups (P < 0.05). We found that the three kinds of anesthesia methods administered to HIV-infected patients could be used with considerable safety and can be selected according to the clinical need and type of surgical procedure.

A nano-opto-mechanical pressure sensor via ring resonator.

This paper reports a nano-opto-mechanical pressure sensor based on nano-scaled ring resonator. The pressure is measured through the output spectrum shift which is induced via mechanical deformation of the ring resonator. The sensitivity as high as 1.47 pm/kPa has been experimentally achieved which agrees with numerical prediction. Due to the strong variation of sensitivity with different ring radius and thickness of the diaphragm, the pressure sensor can be used to form an array structure to detect the pressure distribution in highly accurate measurement with low-cost advantages. The nano-opto-mechanical pressure sensor has potential applications such as shear stress displacement detection, pressure wave detector and pressure mapping etc.

Incidence and survival of symptomatic lacunar infarction in a Beijing population: a 6-year prospective study.

BACKGROUND AND PURPOSE: The incidence of ischaemic stroke has increased or remained high in China; however, little population-based evidence is available on the incidence and survival of lacunar infarction (LAC). We examined the incidence of LAC in a northern Chinese (Beijing) population and monitored survival. METHODS: A prospective registry population-based study was conducted over a 6-year period in a general, unselected, and representative community in Beijing with approximately 100,000 long-term permanent residents. All first-ever stroke cases were registered. RESULTS: A total of 1184 patients with ischaemic stroke were identified; 36.9% (437 cases) were classified as LAC. Age-standardized incidence rates of LAC ranged from 24.0 to 51.3/100,000 with an average rate of 35.3/100,000 during study period. The incidence of LAC increased with age before 70 years. The incidence of non-LAC increased with age. There were no significant differences in crude incidence of LAC between men and women (78.4/100,000 vs. 75.4/100,000). The incidence of non-LAC was significantly higher in men than in women (155/100,000 vs. 107/100,000, P < 0.001). The 28-day case fatality proportions were significantly lower in patients with LAC (0.5%) versus non-LAC (14.9%). One year after acute stroke onset, the survival rates between LAC and non-LAC were similar. CONCLUSION: LAC is a common stroke subtype in Northern China. Men or the elderly are more likely to have non-LAC. Long-term survival following LAC is similar to non-LAC patients.

Numerical and experimental investigation of kerf depth effect on high-frequency phased array transducer.

BACKGROUND: High-frequency ultrasonic transducer arrays are essential for high resolution imaging in clinical analysis and Non-Destructive Evaluation (NDE). However, the structure design and fabrication of the kerfed ultrasonic array is quite challenging when very high frequency (≥100MHz) is required. OBJECTIVE AND METHOD: Here we investigate the effect of kerf depth on the performances of array transducers. A finite element tool, COMSOL, is employed to simulate the properties of acoustic field and to calculate the electrical properties of the arrays, including crosstalk effect and electrical impedance. Furthermore, Inductively Coupled Plasma (ICP) deep etching process is used to etch 36°/Y-cut lithium niobate (LiNbO(3)) crystals and the limitation of etching aspect ratio is studied. Several arrays with different profiles are realized under optimized processes. At last, arrays with a pitch of 25µm and 40µm are fabricated and characterized by a network analyzer. RESULTS: Kerf depth plays an important role in the performance of the transducer array. The crosstalk is proportional to kerf depth. When kerf depth is more than 13µm, the array with crosstalk less than -20dB, which is acceptable for the real application, could provide a desired resolution. Compared to beam focusing, kerf depth exhibits more effect on the beam steering/focusing. The lateral pressure distribution is quantitatively summarized for four types of arrays with different kerf depth. The results of half-cut array are similar to those of the full-cut one in both cases of focusing and steering/focusing. The Full-Width-at-Half-Maximum (FWHM) is 55µm for the half-cut array, and is 42µm for the full-cut one. The 5-µm-cut array, suffering from severe undesired lobes, demonstrates similar behaviors with the no-cut one. ICP process is used to etch the 36°/Y-cut LiNbO(3) film. The aspect ratio of etching profile increases with the kerf width decreasing till it stops by forming a V-shaped groove, and the positive tapered profile angle ranges between 62° and 80°. If the mask selectivity does not limit the process in terms of achievable depth, the aspect ratio is limited to values around 1.3. The measurement shows the electrical impedance and crosstalk are consistent with the numerical calculation. CONCLUSION: The numerical results indicate that half-cut array is a promising alternative for the fabrication of high-frequency ultrasonic linear arrays. In fact, the minimum pitch that could be obtained is around 25µm, equivalent to a pitch of 1.6λ, with a kerf depth of 16µm under the optimized ICP parameters.

Modelling and simulation of high-frequency (100 MHz) ultrasonic linear arrays based on single crystal LiNbO3.

BACKGROUND: High-frequency ultrasonic transducer arrays are essential for high resolution imaging in clinical analysis and Non-Destructive Evaluation (NDE). However, the fabrication of conventional backing-layer structure, which requires a pitch (distance between the centers of two adjacent elements) of half wavelength in medium, is really a great challenge. OBJECTIVE AND METHOD: Here we present an alternative buffer-layer structure with a silicon lens for volumetric imaging. The requirement for the size of the pitch is less critical for this structure, making it possible to fabricate high-frequency (100MHz) ultrasonic linear array transducers. Using silicon substrate also makes it possible to integrate the arrays with IC (Integrated Circuit). To compare with the conventional backing-layer structure, a finite element tool, COMSOL, is employed to investigate the performances of acoustic beam focusing, the influence of pitch size for the buffer-layer configuration, and to calculate the electrical properties of the arrays, including crosstalk effect and electrical impedance. RESULTS: For a 100MHz 10-element array of buffer-layer structure, the ultrasound beam in azimuth plane in water could be electronically focused to obtain a spatial resolution (a half-amplitude width) of 86µm at the focal depth. When decreasing from half wavelength in silicon (42µm) to half wavelength in water (7.5µm), the pitch sizes weakly affect the focal resolution. The lateral spatial resolution is increased by 4.65% when the pitch size decreases from 42µm to 7.5µm. The crosstalk between adjacent elements at the central frequency is, respectively, -95dB, -39.4dB, and -60.5dB for the 10-element buffer, 49-element buffer and 49-element backing arrays. Additionally, the electrical impedance magnitudes for each structure are, respectively, 4kΩ, 26.4kΩ, and 24.2kΩ, which is consistent with calculation results using Krimholtz, Leedom, and Matthaei (KLM) model. CONCLUSION: These results show that the buffer-layer configuration is a promising alternative for the fabrication of high-frequency ultrasonic linear arrays dedicated to volumetric imaging.

Tissue-specific expression and drought responsiveness of cell-wall invertase genes of rice at flowering.

Drought stress near heading reduces grain yield in rice cultivars by inhibiting processes such as anther dehiscence and panicle exsertion. Because cell-wall invertases play an important role in carbon allocation to developing organs, we examined the tissue-specific expression and drought sensitivity of the corresponding genes (OsCIN1-9) at heading in the widely grown cultivar IR64. OsCIN1-5,8 were expressed to varying degrees in flag leaf, panicle, anthers and peduncle at 1 day before heading (1 DBH). When water was withheld for 2 days starting 3 DBH, anthesis and peduncle elongation were halted. At the same time, transcript levels for OsCIN1-5,8 genes were all markedly down-regulated in anthers and/or peduncles but were not affected in flag leaves. Re-watering allowed anthesis and peduncle elongation to proceed and restored expression of OsCIN1-5,8. We conclude that cell-wall invertase genes, as a class, respond rapidly to water deficit in anthers and peduncles and through a reduction in sink strength help to coordinate a delay in anthesis and heading. By contrast, vacuolar invertase OsVIN2 was up-regulated by drought stress in flag leaves, panicles, anthers and peduncles. Although OsCIN1-3,5,8 were active in the peduncle, only OsCIN2 was expressed strongly and preferentially at the base, where cell division and cell elongation occur. OsCIN2 was expressed principally in the primary and secondary vascular systems, consistent with a role in diverting sucrose from the phloem to the dividing and expanding cells of the peduncle, whereas the less abundant OsCIN1,3,5,8 transcripts were found principally in parenchyma cells. The OsCIN2 transcript levels in the base were highest at 1 DBH, when rapid peduncle elongation began. Drought stress halted peduncle elongation and reduced OsCIN2 transcript level to 8% of the control level. On re-watering, peduncle elongation was restored and OsCIN2 transcript level recovered to 24% of the control. The abscisic acid (ABA) level of peduncles increased 7-fold on drought stress and returned to the control level on re-watering. Detached peduncles floated on water elongated little and lost all OsCIN2 transcripts, but on 50-100 microM GA3 they elongated rapidly and maintained high OsCIN2 transcript levels. ABA antagonized both peduncle elongation and maintenance of OsCIN2 transcript levels. We conclude that this antagonism is a potential intervention point for breeding strategies directed at enhancing panicle exsertion during or after drought stress at heading.

Cerebrospinal fluid tau, Abeta1-42 and inflammatory cytokines in patients with Alzheimer's disease and vascular dementia.

In this study we aimed to evaluate the possibility of using cerebrospinal fluid (CSF) tau, Abeta(1-42) and inflammatory cytokines for diagnosis of Alzheimer's disease (AD) and vascular dementia (VD). We measured levels of total tau (T-tau), phospho-tau (P-tau), Abeta(1-42), IL-6, and TNFalpha in CSF in groups of AD, VD, and controls using enzyme-linked immunosorbent assay (ELISA). T-tau level was found significantly higher in groups of AD (t = 3.015, P < 0.01) and VD (t = 2.872, P < 0.01) than in controls. IL-6 level as also higher in AD (t = 2.883, P < 0.01) and VD (t = 3.032, P < 0.01) than in controls. Both T-tau and IL-6 were not significantly different between AD and VD (P > 0.05). The group of AD had remarkably higher P-tau (t = 4.261 and 3.883, respectively, P < 0.01) and lower Abeta(1-42) (t = 3.883 and 4.129, respectively, P < 0.01), as compared with those in VD and controls. TNFalpha level in AD was significantly higher than that in controls (t = 2.745, P < 0.01), but lower than in VD (t = 3.032, P < 0.01). Our data suggested that increment of T-tau and IL-6 levels in CSF was useful for screening AD and VD in certain population, while descending Abeta(1-42) and ascending TNFalpha in CSF are preferable to diagnose AD. In addition, a higher level of CSF P-tau might support AD diagnosis.

[Quantitative analysis of sparfloxacin injection by high performance liquid chromatography].

Analytical method of the quantitative determination of sparfloxacin injection by HPLC is described. The analytical conditions were as follows. A Waters Symmetry C18(5 microns, 150 mm x 3.9 mm i.d.) column was used as the analytical column. The detection wavelength was UV-298.8 nm. The column temperature was 30 degrees C. The mobile phase was 0.2% KH2PO4 buffer (pH 3.2)-CH3CN-CH3OH (80:15:5, volume ratio) and the flow-rate was 1.0 mL/min. The injection volume was 10 microL. The linear range (the peak area vs. the mass concentration of sparfloxacin) was from 39.94 mg/L to 199.68 mg/L, and the correlation coefficient was 0.9999. The average recovery of sparfloxacin was 100.1% (n = 5), and its RSD was 0.72%. The RSDs of continuous injections, within day injections per 2 hours and between day injections in three days were 0.19%, 0.14% and 0.13% respectively. The above analytical results show that this method has good precision and stability. It is a rapid, sensitive and accurate method for the analysis of sparfloxacin.

[Ossification of a protruded lumbar vertebral disc. A report of 17 cases].

From 1973 to 86, 308 patients were operated upon for protruded lumbar vertebral disc. 17 of them had 22 discs protruded and 19 of the 22 discs had been ossified. Operative findings and pathological characteristics of the specimens suggested that the ossified mass could be the result of ossification of the superficial tissue of the protruded disc, a sequence of turnover of fibrocartilage into osseous matter. We are of the confidence that operation is the choice of treatment of such lesion; and it should be performed early following diagnosis, as the ossified mass could never be absorbed, but progress on. The symptoms, lumbago and sciatica, of the 17 patients went immediately off after operation. Follow-up of 16 of them for 1.5 to 7.5 years (averaging 2.5 yrs.) showed excellent and good results in 87.8%.