Effect and mechanism of gomisin D on the isoproterenol induced myocardial injury in H9C2 cells and mice.

We established myocardial injury models in vivo and in vitro to investigate the cardioprotective effect of gomisin D obtained from Schisandra chinensis. Gomisin D significantly inhibited isoproterenol-induced apoptosis and hypertrophy in H9C2 cells. Gomisin D decreased serum BNP, ANP, CK-MB, cTn-T levels and histopathological alterations, and inhibited myocardial hypertrophy in mice. In mechanisms research, gomisin D reversed ISO-induced accumulation of intracellular ROS and Ca2+. Gomisin D further improved mitochondrial energy metabolism disorders by regulating the TCA cycle. These results demonstrated that gomisin D had a significant effect on isoproterenol-induced myocardial injury by inhibiting oxidative stress, calcium overload and improving mitochondrial energy metabolism.

Surpassing the limitation of a coherence length in lidar by digital coherence.

In this manuscript, we propose a digital coherent detection method to surpass the limitation of a coherent length on the detection range of a coherent lidar. This method rapidly reconstructs the laser phase noise utilizing the multi-channel delay self-homodyne and the generalized inverse of the system observation matrix. Subsequently, the reconstructed phase noise is utilized to expunge its perturbation onto the target information in the digital domain, thereby effectively surmounting the coherence length limitation. Through experimentation, the proposed method is verified to produce stable and high-quality interference even when the optical path difference between two beams exceeds 1000 times the coherence length. Additionally, the equivalent laser linewidth is compressed by 105 times.

Hepatoprotective activity of Zha Xun and its different solvent-eluting components / 药学学报

A pharmacophore-based study was conducted to investigate the therapeutic activity of the traditional Tibetan medicine Zha Xun (ZX) in liver diseases. In the present study, the protective effect of ZX on the acute liver injury induced by concanavalin A (ConA) and 0.15% carbon tetrachloride (0.15% CCl4) in ICR mice was evaluated, and the results showed that ZX significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the ConA-induced acute immune liver injury model and the CCl4-induced acute oxidative liver injury model (P < 0.05). Subsequently, the protective effects of aqueous, 95% ethanol, 60% ethanol and 30% ethanol eluting fractions of ZX, and fulvic acid, the main water-soluble constituent of ZX, were evaluated against acute oxidative liver injury induced by 0.15% CCl4 in mice. The results showed that different solvent-eluting fractions of ZX showed certain hepatoprotective activities, among which the aqueous extract of ZX and 30% ethanol extract of ZX significantly reduced the serum levels of ALT, AST, and lactate dehydrogenase (LDH) in mice (P < 0.05), and the serum levels of LDH in mice were significantly reduced by fulvic acid (P < 0.05), which showed significant hepatoprotective activity. The protective activities and preliminary mechanisms of the total extract of ZX, the aqueous extract of ZX, the 30% ethanol extract of ZX, and fulvic acid against hepatocellular injury in vitro were further evaluated by using the H2O2-induced hepatocellular injury model. The results showed that the components could significantly inhibit H2O2-induced hepatocellular injury, reduce the levels of ALT, alkaline phosphatase (ALP), and LDH, improve the survival rate of hepatocellular cells, and reduce the content of intracellular reactive oxygen species (ROS) in cell culture. At the same time, it can inhibit hepatocyte apoptosis by increasing the expression ratio of Bcl-2/BAX protein and decreasing the expression ratio of cleaved caspase-3/pro caspase-3 protein. The present study showed that ZX has clear hepatoprotective activity in vitro and in vivo, and the different solvent elution fractions of ZX showed certain hepatoprotective activity, among which the aqueous extract of ZX, 30% ethanol extract of ZX had better hepatoprotective activity, and the activity of 60% ethanol extract of ZX was stronger than that of 95% ethanol extract of ZX. The activity of ZX and its water-soluble elution site exerted hepatoprotective effects by inhibiting hepatocyte apoptosis and oxidative stress. The animals used in this experiment and related disposal meet the requirements of animal welfare, and have been reviewed and approved by the Laboratory Animal Management and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences (approval number: 00004018).

Long distance high resolution FMCW laser ranging with phase noise compensation and 2D signal processing.

A long distance high resolution frequency-modulated continuous wave (FMCW) laser rangefinder with phase noise compensation and two-dimensional (2D) data processing skills is developed. Range-finding ladar consists of a continuously chirped laser source, an auxiliary reference interferometer, and a monostatic optical transceiver for target illumination and return photon collection. To extend the range unambiguity and lower the electronic processing bandwidth, a two-step laser frequency chirping scheme is adopted, where a long pulse width, small frequency bandwidth laser chirping signal are used in step 1 for coarse distance estimation, and a short pulse width and large frequency bandwidth laser chirping signal are applied afterwards for step 2 high resolution distance realization. An auxiliary reference interferometer is to record the phase noise originated from the laser source to compensate for phase errors induced in the target return photons. The 2D data processing skill helps to coherently sum up all the phase noise removed echo photons to achieve high resolution range peak extraction with high detection sensitivity. Experimental demonstration shows that the proposed FMCW ladar at 1550 nm wavelength with a laser chirping bandwidth of 10 GHz and electronic processing bandwidth of 200 MHz can measure a corner cube test target in an outdoor atmospheric environment, and the measurement results are 12013.905 m with a 2.4 cm range resolution under strong return photon levels and 12013.920 m with a 2.5 cm range resolution under weak return photon levels.

FMCW lidar multitarget detection based on skeleton tree waveform matching.

Frequency-modulated continuous-wave lidar realizes 4D (three-dimensional space and velocity) imaging of the scene by emitting positive and negative frequency sweep laser signals. The premise of it is to identify the frequency points corresponding to the same target in the positive and negative sweep echo signals. For dechirp receiving, there is usually one peak in the frequency spectrum of the positive and negative sweep signals, respectively. Therefore, it is easy to identify and match the peaks. But in a complex environment, the laser beam will irradiate multiple targets at the same time. In addition, beam scanning and target motion cause the echo spectrum to broaden. The above reasons make it extremely difficult to identify and match peaks in practice. To solve this problem, the waveform-matching algorithm based on the skeleton tree is first applied to multitarget echo pairing. The basic idea of the algorithm is to quantify the target echo hierarchically to generate a skeleton tree. The generation of nodes is based on the relative amplitude of waveform peaks and reflects the characteristics of wave crests nesting. Then the similarity of the signal is determined by comparing the distance between the two signal waveform feature trees. Finally, the waveforms are matched in terms of similarity. To further substantiate the role of the proposed algorithm, imaging experiments and related comparative data for different targets have been completed. The results show that the accuracy of matching processed by the algorithm exceeds 90%, which is improved by about 50% compared with not using the algorithm for the target whose overlapping part accounts for a large proportion of itself.

Time Efficiency of Immediate Loading of Full-arch Implant Reconstructions Using Prefabricated Prostheses Located by an Anchor Pin: a Pilot Study.

OBJECTIVE: To investigate the time efficiency of prefabricated prostheses located by an anchor pin stereolithographic attachment system for immediate loading implant reconstruction of completely edentulous jaws and compare it with the conventional protocol. METHODS: Edentulous patients were recruited and randomly assigned into two groups: the full digital workflow group (digital group) and the conventional workflow group (conventional group). In the digital group, a provisional prosthesis was fabricated before surgery using a fully digital workflow and delivered immediately after implant placement. The positioning of the provisional prosthesis was guided precisely by the anchor pin attachment system. In the conventional group, the provisional prosthesis was fabricated after implant placement using a conventional procedure. Clinical and laboratory time efficiency were recorded, and clinician and patient satisfaction were evaluated. RESULTS: Six patients were enrolled in this pilot study and 57 implants were placed following the guided surgery protocol. Of these, 54 were immediately loaded. The total clinical chair time in the digital workflow group was significantly less than that in the conventional workflow group (digital 60.0 ± 13.2 minutes; conventional 106.7 ± 24.7 minutes) (P = 0.045). The total post-surgery procedure took significantly less time in the digital group than the conventional group (digital 202.5 ± 22.5 minutes; conventional 403.7 ± 55.4 minutes) (P = 0.004). The patients' and clinicians' satisfaction with the provisional prostheses was similar in both groups. CONCLUSION: Time efficiency in immediate loading of implant-supported full-arch fixed restorations was improved with prefabricated prostheses located by the anchor-pin-attachment system. Less postoperative chair time was required in the digital group than in the conventional group.

Circadian regulation of breath alcohol concentration.

STUDY OBJECTIVES: The role of the circadian clock in regulating blood/breath alcohol levels after consuming alcohol is uncertain. Our goal was to evaluate the degree to which the circadian system regulates breath alcohol concentration (BrAC) pharmacokinetic parameters. METHODS: Twenty healthy adults aged 21-30 years took part in a 4-day laboratory study. A 40-h constant routine procedure was used to assess circadian rhythms. Every 4 h, participants were given a fixed oral dose of alcohol with breathalyzer measurements taken every 5 min to construct BrAC curves. Sinusoidal models were used to test for circadian variation of the peak BrAC, the time to reach peak BrAC, the absorption rate, the elimination rate, and the time for BrAC to return to zero after alcohol was ingested. RESULTS: A significant circadian rhythm was detected for group-averaged peak BrAC values and the time for BrAC to return to zero, but not other BrAC variables. Peak BrAC values were lowest in the evening near the peak of the core body temperature rhythm and nadir of the salivary cortisol rhythm. Peak BrAC values increased during the night and reached their highest levels in the morning and afternoon. The time needed for BrAC to return to zero was also longest in the late morning and afternoon. CONCLUSION: The circadian system modulates some BrAC pharmacokinetic parameters. In normally entrained individuals, taking the same oral dose of alcohol at different times of day can result in different BrAC responses. These findings have potential implications for alcohol-related accidents and alcohol toxicity.

Feature extraction algorithm of precession target based on image length and Doppler broadening.

In space defense, utilizing the micromotion features to distinguish real targets from interfering targets and decoys is effective. Due to the imaging of the high-speed precession target by microwave radar consisting of isolated scattering centers, there are many difficulties in using inverse synthetic aperture radar (ISAR) images for feature extraction. On the other hand, the inverse synthetic aperture ladar (ISAL) image is relatively continuous because of the short wavelength of laser, and the image sequence contains information about the variation in image length and Doppler width caused by target precession, which can be used for inverse motion parameters. By establishing an observation model of the precession target and performing image processing on the obtained ISAL image at different times, the image length sequence and Doppler width sequence can be obtained. Using the ellipse fitting method to process the obtained sequence, the precession parameters of the target can be obtained. The algorithm does not require prior information such as the radius and speed of the target motion, effectively improving the practicability of the algorithm. Finally, the effectiveness of the algorithm is verified by experimental results, and the error is controlled within 2%.

Accuracy of Intraoral Scanning of Edentulous Jaws with and without Resin Markers.

Objective: To evaluate the accuracy of digital models obtained from intraoral scanning of edentulous maxilla and mandible models with and without resin markers. Methods: A pair of standard edentulous models were scanned using a laboratory scanner and saved as reference models. The edentulous models were fixed onto a phantom head and scanned with an intraoral scanner (IOS) five times each. Six resin markers were attached on the maxilla model and two on the mandible model, and another five intraoral scans were taken of each model. The scanning time and number of images were recorded. The digital models obtained using the IOS were superimposed on the reference models using image processing software. The trueness and precision of the models made using the IOS were evaluated, and the scanning time and number of images were also compared. Results: The average trueness and precision of the IOS in the maxilla model with resin markers were 135.50 ± 36.28 µm and 254.55 ± 40.62 µm, respectively, while those in the mandible were 161.40 ± 55.45 µm and 368.75 ± 91.03 µm, respectively. Placing resin markers on the edentulous maxilla and mandible did not improve the trueness of the IOS, but placing resin markers on the edentulous maxilla improved the precision and scanning efficiency. However, placing resin markers on the buccal shelf of the edentulous mandible decreased the precision and increased the scanning time. Conclusion: Resin markers placed on the hard palate of edentulous maxillae could improve the precision of the IOS and improve scanning efficiency. However, they did not affect the trueness of the IOS for edentulous maxillae or mandibles.

Comparison of the registration methods for the three-dimensional facial scans applied to the design of full-arch implant supported restoration / 北京大学学报(医学版)

OBJECTIVE@#To compare the registration accuracy of three-dimensional (3D) facial scans for the design of full-arch implant supported restoration by five methods and to explore the suitable registration method.@*METHODS@#According to the criteria, ten patients with maxillary edentulous jaw or end-stage dentition requiring implant supported restorations were enrolled in this study. A special rim with individual feature marks reflected appropriate occlusal relationship and esthetic characteristics was made for each patient. Both 3D facial scan data of natural laughter and with opener traction to expose the teeth or occlusal rim of each patient were acquired by facial scan and input to the digital analysis software Geomagic Qualify 2012. The dataset was superimposed by five different methods: seven facial anatomical landmark points alignment, facial immobile area alignment (forehead and nasal area), facial anatomical landmark points and immobile area combining alignment, facial feature points alignment, facial and intraoral feature points alignment with the same local coordinate system. The three-dimensional deviation of the same selected area was calculated, the smaller the deviation, the higher the registration accuracy. The 3D deviation was compared among the three registration methods of facial anatomical landmark points, facial immobile area alignment and the combination of the above two methods. Friedman test was performed to analyze the difference among the three methods (α=0.05). The effect of the aid of the facial and intraoral feature points were evaluated. Paired t test were performed to analyze the difference (P<0.05).@*RESULTS@#The average three-dimensional deviation of the selected area after alignment with the facial anatomical landmarks was (1.501 2±0.406 1) mm, significantly larger than that of the facial immobile area best-fit alignment [(0.629 1±0.150 6) mm] and the combination of the two methods[(0.629 1±0.150 6) mm] (P < 0.001). The aid of the facial feature points could significantly reduce the deviation (t=1.001 3, P < 0.001). There was no significant statistical difference in the remaining groups.@*CONCLUSION@#The forehead area of the 3D facial scan can be exposed as much as possible. The establishment of facial characteristic landmark points and the use of the invariant area alignment can improve the accuracy of registration. It should be clinically feasible to apply three-dimensional facial scan to the design of full-arch implant supported restoration with the registration of the immobile area on the face especially the forehead area.

Inverse synthetic aperture ladar autofocus imaging algorithm for micro-vibrating satellites based on two prominent points.

As an important imaging method for long-range satellite targets, inverse synthetic aperture ladar (ISAL) has the characteristics of high-resolution imaging and competitive detectability. Since the working wavelength of the ISAL is comparable to the micro-vibrations generated by mechanical moving components of satellites, which will cause image defocusing, motion compensation is of great significance. In this paper, an autofocus algorithm is proposed for estimating and compensating the phase error relating to both translational and rotational micro-vibrations. Comparing with non-parametric algorithms like phase gradient autofocus and parametric algorithms like contrast-based autofocus and entropy-based autofocus, the proposed one, which is based on two prominent points, is especially effective for the rotational phase error oscillating numbers of cycles. Simulations and experiments are conducted to validate the feasibility of the proposed algorithm.

Feature extraction algorithm of a precession target based on a Doppler frequency profile of dual-aspect observation.

In ballistic missile defense, using precession parameters is an effective way to determine warheads from decoys. Due to the geometric theory of diffraction, the backscattered field from a smooth object for a microwave radar consists of contributions from only isolated scattering centers. Further, thanks to the short wavelength of the laser, the ladar could obtain complete Doppler information of illuminated parts of precessing targets. On the basis of modeling the observation geometry of a rotating target with precession, a novel method for extracting precession parameters using coherent ladar based on a Doppler frequency profile (DFP) of dual-view observation is first proposed, to the best of our knowledge. By analyzing the periodic changes of bandwidth of a cone-shaped precessing object, we indicate that the sequence of DFP bandwidth can be approximate to a sinusoid function, based on which the precession period can be obtained through sinusoidal fitting. The precession angle can be obtained by combining dual-aspect receiving observation. A laboratory experiment verified the effectiveness of the proposed algorithm, and the errors of extracted parameters are about 10%.

Single-frequency LADAR super-resolution Doppler tomography for extended targets.

Doppler tomography is an important means to obtain two-dimensional (2-D) images of remote targets. It is especially suitable for imaging spinning targets such as space debris, warheads, and aircraft blades. However, related research is mostly focused on the microwave band rather than the laser. Higher resolution can be achieved by implementing Doppler tomography in the laser band compared to the existing Doppler tomography in the microwave. Moreover, existing imaging methods are mostly directed at point targets. When these methods deal with extended target echoes, the image quality is unsatisfactory. These problems severely limit the application of Doppler tomography. Here, a novel laser Doppler tomography method has been proposed. The method is based on a single-frequency laser radar (LADAR) that does not require any form of wideband modulation of the transmitted signal. The imaging process is based on the precise relationship between the scattering coefficient of the target and the statistical characteristics of the Doppler spectrum and finds the maximum a posteriori (MAP) estimate of the scattering coefficient distribution. The imaging resolution depends on the Doppler frequency resolution, which exceeds the diffraction limit and is independent of the imaging distance. A laser Doppler tomography experimental system was established. With this system, high-quality laser Doppler tomograms of extended targets were obtained for the first time. In the experiment, the targets have different rotational speeds from 100 to 1000 r/min. The images of these targets with a resolution of 0.4 mm are obtained at a distance of 5 m indoors. In these images, the target details such as textures on the surfaces can be rendered. The quality of these images is greatly improved compared to existing processing methods. The experimental results confirm the effectiveness of the proposed laser Doppler tomography method.

Oral hygiene maintenance of locator attachments implant overdentures in edentulous population: A longitudinal study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the oral hygiene status of edentulous patients with locator attachments implant overdentures (IOD) and to analyze the relationship among daily hygiene behavior, oral hygiene status and peri-implant diseases.@*METHODS@#Edentulous patients who received IOD treatment with locator attachments from January 2012 to May 2016 were recruited. Clinical and radiographic examinations were conducted to assess the peri-implant tissue status. Modified plaque index (mPLI), sulcus bleeding index (SBI), gingival index (GI), and probing depth (PD) were recorded and peri-implant marginal bone loss (MBL) was measured using paralleling projection technique. Patients' peri-implant oral hygiene maintainence habits were investigated. The correlation between peri-implant diseases and oral hygiene status and behaviors was analyzed.@*RESULTS@#Fifty patients (125 implants) with an average follow-up time of 22 months (6-54 months) were enrolled. The mean values of mPLI, SBI, and GI were 1.4±1.2, 0.8±0.7, and 0.7± 0.6, respectively. Average PD was (2.2±0.7) mm. Mesial and distal maginal bone resorptions were (1.1±1.1) mm and (0.9±0.9) mm, respectively. The prevalance of mucositis and peri-implantitis of the implants were 49.6% and 0. The prevelance of mucositis in the patients with poor oral hygiene (mPLI≥2) was 11.9 times as much as that of those with adequate oral hygiene (mPLI<1). The patients who performed oral hygiene procedure on attachments at least twice a day achieved much lower mPLI scores than those who cleaned less than twice a day.@*CONCLUSION@#Oral hygiene condition in the group of patients with implant overdentures was poor, and it contributed to increased risk of peri-implant mucositis. The prevelance of musositis of the paitients with poor oral hygiene was 11.9 times as much as that of those with proper oral hygiene. Patients wearing IOD should pay more attention to the hygiene of the attachments.

Medical waste management in three areas of rural China.

OBJECTIVE: The purpose of this paper is to describe current practices of medical waste management, including its generation, investments, collection, storage, segregation, and disposal, and to explore the level of support from upper tiers of the government and health care system for medical waste management in rural China. METHODS: The authors draw on a dataset comprised of 209 randomly selected rural township health centers (THCs) in 21 counties in three provinces of China: Anhui, Shaanxi and Sichuan. Surveys were administered to health center administrators in sample THCs in June 2015. RESULTS: The results show that the generation rate of medical waste was about 0.18 kg/bed, 0.15 kg/patient, or 0.13 kg/person per day on average. Such per capita levels are significant given China's large rural population. Although investments of medical waste facilities and personnel in THCs have improved, results show that compliance with national regulations is low. For example, less than half of hazardous medical waste was packed in sealed containers or containers labeled with bio-hazard markings. None of the THCs segregated correctly according to the categories required by formal Chinese regulations. Many THCs reported improper disposal methods of medical waste. Our results also indicate low levels of staff training and low rates of centralized disposal in rural THCs. CONCLUSIONS: Medical waste is a serious environmental issue that is rising on the agenda of policymakers. While a large share of THCs has invested in medical waste facilities and personnel, it appears that actual compliance remains low. Using evidence of low rates of training and centralized disposal, we surmise that a lack of support from upper tiers of management is one contributing factor. Given these findings, we recommend that China's policymakers should enhance support from upper tiers and improve monitoring as well as incentives in order to improve medical waste management.

Will Happiness Improve the Psychological Integration of Migrant Workers?

Happiness is a major factor that influences people’s perceptions and behavior. Two-stage least squares regression was applied to investigate the effect of happiness on the psychological integration of migrant workers in China. The data for a total of 1625 individuals were obtained from the 2014 China Labor-force Dynamics Survey (CLDS). This study describes happiness from three main aspects: happiness, life satisfaction, and economic satisfaction. The psychological integration includes two dimensions of settlement willingness, and trust level; these have gone through dimension-reduced processing by using the weighted average method. The empirical evidence shows, first, that happiness has a significantly positive effect on the psychological integration of migrant workers and second, that the sense of life satisfaction in particular plays a more significant role. The acceleration of the social and political integration in migrant workers will enhance their psychological integration. Additionally, social, cultural and economic integration is found to influence migrant workers’ psychological integration by promoting happiness. Happiness between different generations of migrant workers was found to have a noticeably positive impact on their psychological integration; however, the happiness of the younger migrant workers was more perceivable than that of the other generations. Preferential policies should therefore be provided to improve the happiness of migrant workers.

Three-dimensional inverse synthetic aperture lidar imaging for long-range spinning targets.

We present a three-dimensional (3D) imaging method for long-range spinning targets. This method acquires multi-angle two-dimensional (2D) images of spinning targets by the inverse synthetic aperture lidar (ISAL) imaging technique. The 3D distribution of the scattering coefficients of a target has a mapping relationship with the series of 2D images. This mapping is analyzed, and a 3D Hough transform is used to implement inverse mapping. The parameter space of the Hough transform is the estimation of the 3D distribution of the scattering coefficients. The 3D point spread function obtained by the method has narrow main lobe widths and sufficiently low side lobes to achieve high image quality, which is verified by computer simulations. In the simulations, the main lobe widths in the three dimensions are 0.29 cm, 0.29 cm, and 3.48 cm, respectively. In outdoor experiments, 3D images of targets at 1 km away from the lidar were obtained. The images clearly show the 3D shape of targets.

Inverse synthetic aperture LADAR demonstration: system structure, imaging processing, and experiment result.

A long-distance inverse synthetic aperture LADAR (ISAL) imaging experiment outdoors over 1 km for cooperative targets is demonstrated, which gets a two-dimensional high-resolution image with resolution exceeding 2.5 cm. The system utilizes an electro-optic in-phase and quadrature modulator to output a linear frequency-modulated continuous waveform (LFMCW) with a bandwidth of 6 GHz and pulse repetition frequency (PRF) of 16.7 KHz. For the problem of the coherence of the laser, the effects of the coherent processing interval (CPI) and time delay of the local oscillator (LO) on the coherence are discussed. The fiber delay line is set and the CPI is reduced to lower the requirement of the frequency stability of the laser source. The images are formed by two-dimensional Fourier transform and joint time-frequency transform methods, respectively. In this paper, we present the system structure, imaging processing, and the experiment result in detail. The experiment result validates the performance of our system for ISAL imaging.

The gender gap among school children in poor rural areas of western China: evidence from a multi-province dataset.

BACKGROUND: The gender gap remains a major impediment in the path towards equality and it is especially wide in low-income countries. Up to the early 2000s, many studies documented extensive inequalities in China: girls had poorer health, less nutrition and less education than their male counterparts. The goal of this study is to examine whether the gender gap persists, given that China is now making the transition into the ranks of upper-middle income countries. We consider educational outcomes, mental and physical health status, as well as non-cognitive outcomes. METHODS: We draw on a dataset containing 69,565 observations constructed by combining data from 7 different school-level surveys spanning 5 provinces. The surveys were all conducted by the authors between 2008 and 2013 using uniform survey instruments and data collection protocols in randomly selected schools across western provinces in rural China. The sample children range in age from 9 to 14 years (with 79 % of the sample being aged 10 to 12). Our analysis compares rural girls with rural boys in terms of 13 different indicators. RESULTS: With the exception of anemia rates, the health outcomes of girls are equal to those of boys. Girls and boys are statistically identical in terms of weight-for-age, height-for-age, and prevalence of intestinal worm infections. Girls performed better than boys on five of six cognitive and educational performance indicators. Girls performed worse than boys on all mental health indicators. All estimates are robust to the inclusion of different age ranges, controlling for the level of household assets, ethnic minority status, as well as the addition of provincial dummies. CONCLUSIONS: Our findings suggest that with the exception of non-cognitive outcomes, anemia and standardized math test scores, the gender gap in our study areas in China appears to be diminishing.

Synthesis and potent inhibitory activities of carboxybenzyl-substituted 8-(3-(R)-aminopiperidin-1-yl)-7-(2-chloro/cyanobenzyl)-3-methyl-3,7-dihydro-purine-2,6-diones as dipeptidyl peptidase IV (DPP-IV) inhibitors.

Fourteen 3-methyl-3,7-dihydro-purine-2,6-dione derivatives 1-14 bearing carboxybenzyl and 2-chloro/cyanobenzyl groups at the N-1 and N-7 positions, respectively, were synthesized as dipeptidyl peptidase IV (DPP-IV) inhibitors. These compounds were characterized on the basis of NMR ((1)H and (13)C) and ESI MS data. In vitro bioassay indicates that most of these compounds showed moderate to good inhibitory activities against DPP-IV. Among them, compound 13 (IC50=36 nM) exhibited comparable activity with a positive control, Sitagliptin (IC50=16 nM). In addition, the structure-activity relationship of these compounds is also briefly discussed.