Palaeobotanical evidence reveals the living conditions of Miocene Lufengpithecus in East Asia.

BACKGROUND: Understanding the relationship between human evolution and environmental changes is the key to lifting the veil on human origin. The hypothesis that environmental changes triggered the divergence of humans from apes (ca. 9.3-6.5 million years ago, Ma) has been poorly tested because of limited continuous environmental data from fossil localities. Lufengpithecus (12.5-6.0 Ma) found on the southeastern margin of the Tibetan Plateau (SEMTP) across the ape-human split provides a good chance for testing this hypothesis. RESULTS: Here, we reconstructed the habitats of L. keiyuanensis (12.5-11.6 Ma) with comprehensive vegetation, climate, and potential food web data by palaeobotanical evidence, together with other multidisciplinary data and partly tested the environment-driven hypothesis by revealing the living conditions of Lufengpithecus. CONCLUSION: A detailed comparison of hominoids on different continents reveals their behaviour and fate divergence across the ape-human split against the background of global climate change, i.e., the stable living conditions of SEMTP not only provided a so-called 'refuge' for arboreal Lufengpithecus but also acted as a 'double-edged sword', preventing their further evolution while vegetation shifts in East Africa probably stimulated the emergence of human bipedalism, and the intense climatic changes in Europe possibly prevented those hominoids from surviving that time interval. Our findings provide interesting insight into the environmental impacts on the behavioural evolution of hominoids.

Typical polar organic aerosol tracers in PM2.5 over the North China Plain: Spatial distribution, seasonal variations, contribution and sources.

PM2.5 samples were collected simultaneously at three urban sites including Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ) and one background site Xinglong (XL) from June 2014 till April 2015. Typical polar organic aerosol tracers including 2-methylglyceric acid, 2-methyltetrols, 3-hydroxyglutaric acid, anhydrous saccharides and phthalic acid were analyzed by gas chromatography-mass spectrometry. Both Isoprene secondary organic aerosol (SOA) tracers and pinene SOA tracers had higher mass concentrations at background site than those at urban sites. But they showed different seasonal variations. The former had the highest mass concentration in summer while the latter had the highest mass concentration in spring. Anhydrous saccharides and phthalic acids at urban sites had higher mass concentrations than those at background site and showed higher mass concentration in autumn and winter, respectively. Corresponding estimated secondary organic carbons (SOCs) showed similar variation trends with tracers. In general, biogenic sources had more influence on background site while urban sites were more affected by anthropogenic sources.

Dynamic status of metabolically healthy overweight/obesity and metabolically unhealthy and normal weight and the risk of type 2 diabetes mellitus: A cohort study of a rural adult Chinese population.

OBJECTIVE: We aimed to determine dynamic status of metabolically healthy overweight or obesity (MHO) and metabolically unhealthy and normal weight (MUNW) and the risk of incident type 2 diabetes mellitus (T2DM). METHODS: Body mass index and metabolic health were assessed on 11,865 eligible participants ≥18 years from 6-year follow-up cohort study of a rural Chinese population. Participants were classified as metabolically healthy and normal weight (MHNW), MHO, MUNW and metabolically unhealthy overweight or obesity (MUO) at both baseline and follow-up examinations. Hazard ratio (HR) and 95% confidence interval (CI) were used to assess baseline and their changes of BMI-metabolic status and the risk of incident T2DM. RESULTS: Risk of T2DM was increased for all participants with baseline MHO, MUNW, and MUO (adjusted HR 1.94, 95% CI 1.33-2.81; 3.10, 95% CI 2.19-4.39; and 6.63, 95% CI 4.94-8.90, all P<0.001, respectively). However, risk of T2DM was increased for participants with transformation from MHO to MUO (4.52, 95% CI 2.42-8.47, P<0.001) as compared with stable MHNW, but not stable MHO (0.53, 95CI 0.20-1.40, P=0.20). Risk of T2DM did not differ between participants with transformation from MUNW to metabolically healthy and those with stable MHNW (P>0.05), but was increased with stable MUNW (5.78, 95% CI 3.15-10.62, P<0.001). The results were consistent when analyses were restricted to participants without baseline impaired fasting glucose level. CONCLUSIONS: Our findings provide understanding for differentiating high-risk individuals for incident T2DM in Chinese population.

[Mechanisms of human telomerase reverse transcriptase RNAi which increases hepatocellular carcinoma cell apoptosis induced by TRAIL].

OBJECTIVES: To investigate the mechanisms for human telomerase reverse transcriptase (hTERT) RNA interference (RNAi) in increasing hepatocellular carcinoma cell apoptosis induced by TNF-related apoptosis-inducing ligand (TRAIL). METHODS: Cell apoptosis was identified by flow cytometry analysis after annexin V/PI double staining. Expression of apoptosis-related proteins, procaspase-8, -9, -3, Bax, Bcl-2 and hTERT, were identified by Western blotting analysis; telomerase activity and telomere length were detected by telomeric repeat amplification protocol (TRAP) and telomere amount and length assay (TALA) methods. RESULTS: Hepatocellular carcinoma cell apoptosis induced by TRAIL were all significantly increased by hTERT RNAi (P less than 0.05). For example, apoptosis rates were enhanced from 5.53% (untransformed) to 10.35% (transformed) in HepG 2 cells and from 14.73% to 77.24% in SMMC 7721 cells after being treated by 100 ng/ml TRAIL for 24 h. Moreover, activation of procaspase-8, -9 and -3 in transformed cells after being treated by TRAIL were all significantly raised (P less than 0.05) in a dose-dependent manner. The expression of procaspase-8, -9 and Bcl-2 were effectively augmented (P less than 0.05), but expressions of Bax and hTERT were strikingly decreased (P less than 0.05). Meanwhile, telomerase activity was apparently suppressed and telomere length was markedly shortened (P less than 0.05). There were no remarkable differences in these effects between control cells and the untransformed cells (P more than 0.05). CONCLUSION: Enhanced cell apoptosis induced by TRAIL through hTERT RNAi may be related to up-regulation of procaspase-8 and -9 expressions. However the down-regulation of hTERT expression, reduced telomerase activity and shortened telomere length may not be related to expressions of Bcl-2 and Bax.

Near infrared surface-enhanced Raman scattering based on star-shaped gold/silver nanoparticles and hyperbolic metamaterial.

It is desirable to extend the surface-enhanced Raman scattering (SERS) from the conventionally used visible range into the infrared region, because the fluorescence background is lower in the long-wavelength regime. To do this, it is important to have a SERS substrate suitable for infrared operation. In this work, we report the near infrared SERS operation based on the substrates employing star-shaped gold/silver nanoparticles and hyperbolic metamaterial (HMM) structure. We first fabricate the SERS substrate in which nanoparticles are separated from a silver film by a thin dielectric layer. Performance of the SERS substrate is investigated with a 1064-nm excitation source. Compared with similar silver film-based substrates employing respectively gold and silver spherical nanoparticles, it is found that, Raman intensity scattered by the substrate with star-shaped nanoparticles is 7.4 times stronger than that with gold nanoparticles, and 3.4 times stronger than that with silver nanoparticles. Following this, we fabricate the SERS substrate where the star-shaped nanoparticles are deposited over a HMM structure. The HMM structure comprises three pairs of germanium-silver multilayers. Further experimental result shows that, with the star-shaped nanoparticles, the HMM-based substrate yields 30% higher Raman intensity for near infrared SERS operation than the silver film-based substrate does.

Association of type 2 diabetes mellitus with the interaction between low-density lipoprotein receptor-related protein 5 (LRP5) polymorphisms and overweight and obesity in rural Chinese adults.

BACKGROUND: Low-density lipoprotein receptor-related protein 5 (LRP5) plays an important role in glucose and cholesterol metabolism. The present cohort study evaluated associations of LRP5 variants with the incidence of type 2 diabetes mellitus (T2DM) in a rural adult Chinese population. METHODS: In all, 7751 subjects aged ≥18 years without T2DM underwent genotyping at baseline; 6326 subjects (81.62%) were followed-up, and 5511 with a clear disease outcome were eligible for analysis. The same questionnaire was administered and the same anthropometric and blood biochemical examinations were performed at baseline and follow-up. Association analysis was performed for five single nucleotide polymorphisms and haplotypes of LRP5. RESULTS: Cox proportional hazards testing of three different genetic models found no significant association between T2DM and LRP5 after adjusting for potential risk factors (P > 0.05). However, the incidence of T2DM in subjects with LRP5 mutational genotypes was higher in the overweight/obese than normal weight population. Under the dominant model, the risk of T2DM was increased with an interaction between rs11228303 and the waist-to-height ratio adjusted for baseline age, sex, and family history of T2DM (synergy index [SI] = 4.172; 95% confidence interval [CI] 1.014-17.166)], and body mass index (SI = 3.237; 95% CI 1.102-9.509). Furthermore, the A allele of rs3758644 was related to decreased fasting plasma insulin and homeostatic model assessment of ß-cell function levels, whereas the T allele of rs12363572 was related to increased high-density lipoprotein cholesterol levels in new-onset diabetes patients (P < 0.05). CONCLUSIONS: The risk of T2DM may be associated with interactions between the LRP5 gene and overweight and obesity. Polymorphisms of LRP5 are related to ß-cell function and lipid metabolism.

Effect of Helicobacter pylori infection on Bax protein expression in patients with gastric precancerous lesions.

AIM: To investigate the effect of Helicobacter pylori (H pylori) infection on Bax protein expression, and explore the role of H pylori in gastric carcinogenesis. METHODS: H pylori was assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions. RESULTS: Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in H pylori-positive gastric precancerous lesions (72.3%) was significantly higher than that in H pylori-negative gastric precancerous lesions (48.0%, chi2 = 4.191, P<0.05). H pylori infection was well correlated with the expression of Bax protein in gastric precancerous lesions (r = 0.978, P<0.01). After eradication of H pylori, the positivity of Bax protein expression significantly decreased in H pylori-positive gastric precancerous lesions (chi2 = 5.506, P<0.05). In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed. CONCLUSION: H pylori infection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of H pylori infection-induced gastric epithelial cell apoptosis. H pylori might act as a tumor promoter in the genesis of gastric carcinoma and eradication of H pylori could inhibit gastric carcinogenesis.

High-resolution summer precipitation variations in the western Chinese Loess Plateau during the last glacial.

We present a summer precipitation reconstruction for the last glacial (LG) on the western edge of the Chinese Loess Plateau (CLP) using a well-dated organic carbon isotopic dataset together with an independent modern process study results. Our results demonstrate that summer precipitation variations in the CLP during the LG were broadly correlated to the intensity of the Asian summer monsoon (ASM) as recorded by stalagmite oxygen isotopes from southern China. During the last deglaciation, the onset of the increase in temperatures at high latitudes in the Northern Hemisphere and decline in the intensity of the East Asia winter monsoon in mid latitudes was earlier than the increase in ASM intensity and our reconstructed summer precipitation in the western CLP. Quantitative reconstruction of a single paleoclimatic factor provides new insights and opportunities for further understanding of the paleoclimatic variations in monsoonal East Asia and their relation to the global climatic system.

[Supraorbital keyhole approach in the treatment of intranasal meningoencephaloceles].

OBJECTIVE: To explore the effect and significance of endoscopic surgery for intranasal meningoencephaloceles via the supraorbital keyhole approach. METHODS: From January 1999 to December 2001, seven cases of intranasal meningoencephaloceles were treated by mini-invasive endoscopic surgery via supraorbital keyhole approach. The operation was carried out through supraorbital keyhole craniotomy approximately 2.0-2.5 cm in diameter following a skin incision just in the eyebrow. The roughly 3-4 cm skin incision began medial to the supraorbital nerve and ended within the lateral edge of the eyebrow. After the frontal lobe was elevated and the skull base defects exposed, the hernia sac was cut off at bone defect and the lump was resected via nasal cavity. The bone defect were repaired using bone flap, self fat, fascia of rectus abdominis muscle and Ear-Brain Glue. RESULTS: Seven patients were successfully treated at initial operation without recurrence and cerebrospinal fluid leak during follow-up 6 months to 2 years after surgery. CONCLUSION: The supraorbital keyhole approach is a safe approach in the hands of experienced surgeons for the mini-invasive treatment of meningoencephaloceles.