Impact of Microbubble Degradation and Flow Velocity on Subharmonic-aided Pressure Estimation (SHAPE): An Experimental Investigation

OBJECTIVE

This study aimed to investigate the impact of microbubble degradation and flow velocity on Sub-Harmonic Aided Pressure Estimation (SHAPE), and to explore the correlation between subharmonic amplitude and pressure as a single factor.

METHODS

We develop an open-loop vascular phantom platform system and utilize a commercial ultrasound machine and microbubbles for subharmonic imaging. Subharmonic amplitude was measured continuously at constant pressure and flow velocity to assess the impact of microbubble degradation. Flow velocity was varied within a range of 4-14 cm/s at constant pressure to investigate its relationship to subharmonic amplitude. Furthermore, pressure was varied within a range of 10-110 mm Hg at constant flow velocity to assess its isolated effect on subharmonic amplitude.

RESULTS

Under constant pressure and flow velocity, subharmonic amplitude exhibited a continuous decrease at an average rate of 0.221 dB/min, signifying ongoing microbubble degradation during the experimental procedures. Subharmonic amplitude demonstrated a positive correlation with flow velocity, with a variation ratio of 0.423 dB/(cm/s). Under controlled conditions of microbubble degradation and flow velocity, a strong negative linear correlation was observed between pressure and subharmonic amplitude across different Mechanical Index (MI) settings (all R2 > 0.90). The sensitivity of SHAPE was determined to be 0.025 dB/mmHg at an MI of 0.04.

CONCLUSION

The assessment of SHAPE sensitivity is affected by microbubble degradation and flow velocity. Excluding the aforementioned influencing factors, a strong linear negative correlation between pressure and subharmonic amplitude was still evident, albeit with a sensitivity coefficient lower than previously reported values.

Nucleophile-Controlled Trapping of Gold Carbene by Nitriles and Water: Synthesis of 5H-Pyrimido[5,4-b]indoles and 2-Benzylidene-3-indolinones

A gold-catalyzed, nucleophile-controlled cascade reaction of N-(2-azidophenyl-ynyl)methanesulfonamides with nitriles and water is described that provides structurally diverse 5H-pyrimido[5,4-b]indoles and 2-benzylidene-3-indolinones in good to excellent yields. Mechanistic studies indicate that the β-sulfonamido-α-imino gold carbene is the key intermediate which is generated through the gold-catalyzed cyclization of N-(2-azidophenyl-ynyl)methanesulfonamides and undergoes formal [4 + 2] cascade annulation with nitriles and intramolecular SN2' type reaction with water, respectively.

[Relationship between the neutrophil-to-lymphocyte ratio and estimated glomerular filtration rate in patients with primary aldosteronism: a cross-sectional study]

Objective: To investigate the associations between neutrophil-to-lymphocyte ratio (NLR) and estimated glomerular filtration rate (eGFR) in patients with primary aldosteronism (PA). Methods: This study was a cross-sectional study. Consecutive patients diagnosed with PA and admitted to the Second Affiliated Hospital of Nanchang University from October 2017 to April 2022 were enrolled. General information, blood routine, renal function, and other clinical data of the patients were collected. Based on the median NLR of the enrolled patients, NLR Collapse

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MESH Headings

• Humans
• Female
• Male
• Neutrophils
• Glomerular Filtration Rate
• Cross-Sectional Studies
• Lymphocytes
• Hyperaldosteronism/diagnosis
• Hyperlipidemias

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Grants

• 3226090026, 81960088 National Natural Science Foundation of China

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Affiliation(s)

N Li Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
J Qiu Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
N P Liang Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
M B Wu Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
X T Zhang Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
H Zhang Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
Y F Dong Cardiovascular Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China Key Laboratory of Molecular Biology in Jiangxi Province, Nanchang 330006, China

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Quantification of the renal sinus fat and exploration of its relationship with ectopic fat deposition in normal subjects using MRI fat fraction mapping

Purpose

To determine the renal sinus fat (RSF) volume and fat fraction (FF) in normal Chinese subjects using MRI fat fraction mapping and to explore their associations with age, gender, body mass index (BMI) and ectopic fat deposition.

Methods

A total of 126 subjects were included in the analysis. RSF volume and FF, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) area, and hepatic and pancreatic FFs were measured for each subject. The comparisons in gender were determined using two-tailed t-tests or the nonparametric Mann-Whitney U-test for normally or non-normally distributed data for continuous variables and the chi-square test for categorical variables. Comparisons of RFS volume and FF between right and left kidneys were determined using paired sample t-tests. Multivariable logistic models were performed to confirm whether RSF differences between men and women are independent of VAT or SAT area. When parameters were normally distributed, the Pearson correlation coefficient was used; otherwise, the Spearman correlation coefficient was applied.

Results

The RSF volumes (cm3) of both kidneys in men (26.86 ± 8.81 for right and 31.62 ± 10.32 for left kidneys) were significantly bigger than those of women (21.47 ± 6.90 for right and 26.03 ± 8.55 for left kidneys) (P < 0.05). The RSF FFs (%) of both kidneys in men (28.33 ± 6.73 for right and 31.21 ± 6.29 for left kidneys) were significantly higher than those of the women (23.82 ± 7.74 for right and 27.92 ± 8.15 for left kidneys) (P < 0.05). The RSF differences between men and women are independent of SAT area and dependent of VAT area (except for right RSF volume). In addition, the RSF volumes and FFs in both kidneys in the overall subjects show significant correlations with age, BMI, VAT area, hepatic fat fraction and pancreatic fat fraction (P < 0.05). However, the patterns of these correlations varied by gender. The RSF volume and FF of left kidney were significantly larger than those of the right kidney (P < 0.05).

Conclusion

The association between renal sinus fat and ectopic fat deposition explored in this study may help establish a consensus on the normal values of RSF volume and FF for the Chinese population. This will facilitate the identification of clinicopathological changes and aid in the investigation of whether RSF volume and FF can serve as early biomarkers for metabolic diseases and renal dysfunction in future studies.

Vascular toxicity of multi-walled carbon nanotubes targeting vascular endothelial growth factor

Multiwalled carbon nanotubes (MWCNTs) are currently widely used and are expected to be used as drug carriers and contrast agents in clinical practice. Previous studies mainly focused on their lung toxicity; therefore, their effects on the vascular endothelium are unclear. In this study, a human angiogenesis array was used to determine the effect of MWCNTs on the expression profile of angiogenic factors in endothelial cells and to clarify the role of vascular endothelial growth factor (VEGF) in MWCNT-induced endothelial cell injury at the cellular and animal levels. The results indicated that MWCNTs (20-30 nm and 30-50 nm) could enter endothelial cells and disrupt human umbilical vein endothelial cell (HUVECs) activity in a concentration-dependent manner. MWCNTs disrupted the tube formation ability and cell migration function of HUVECs. The results from a Matrigel Plug experiment in mice showed that angiogenesis in the MWCNT experimental group was significantly reduced. The results of a protein chip analysis indicated that VEGF expression in the MWCNT treatment group was decreased, a finding that was validated by ELISA results. The protein expression levels of AKT and eNOS in the MWCNT treatment group were significantly decreased; the administration of recombinant VEGF significantly alleviated the migration ability and tube formation ability of endothelial cells injured by MWCNTs, upregulated the protein expression of AKT and eNOS, and increased the number of neovascularization in mice in the MWCNT treatment group. This study demonstrated that MWCNTs affect angiogenesis via the VEGF-Akt-eNOS axis which can be rescued by VEGF endothelial treatment.

An angular-resolved scattered-light diagnostic for laser-plasma instability studies

We developed an angular-resolved scattered-light diagnostic station (ARSDS) to extend the study of laser-plasma instabilities (LPIs) by simultaneously diagnosing their features at different angles in a single shot. The ARSDS angularly samples the scattered light using an array of fibers with flexible setups. The collected light is detected with an imaging spectrometer, a streaked spectrometer, or a fiber-optic spectrometer to provide time-integrated/time-resolved spectral information. The ARSDS was implemented at Shenguang-II Upgrade laser facility for the double-cone ignition campaigns. Preliminary results confirm the importance of an angular-resolved detection due to the angular dependence of LPI processes, such as stimulated Raman scattering.

[Sedimentary Diatom Records Reveal the Succession of Ecosystem in Lake Xihu, Dali over the Past 50 Years]

In recent decades, intense human activities have caused a decline in many lake ecosystems in Yunnan Province, rendering the transformation of the lake from a clear macrophyte-dominated state to a turbid phytoplankton-dominated state. Improved understanding of the ecological changes in lake ecosystem has significant implications for management. In this study, a small lake in Dali Prefecture of Yunnan Province, i.e., Lake Xihu, was selected. Combined with diatom records and physicochemical proxies from the lake sediments, this paper focuses on the long-term ecological changes in Lake Xihu, Dali since the mid-1960s. The results show that the Lake Xihu, Dali has undergone a significant shift in stable states over the past 50 years. Prior to 2000, the benthic-epiphytic species (i.e., Cocconeis placentula, Staurosira construens, Gomphonema angustum, and Achnanthidium minutissimum) dominated in diatom assemblages, indicating oligotrophic conditions; since 2000, benthic-epiphytic species (i.e., Encyonopsis microcephala and Navicula cryptocephala) and planktonic species (i.e., Cyclotella atomus, Cyclotella meneghiniana, Stephanodiscus hantzschii, and Aulacoseira granulata) dominated successively, indicating mesotrophic to eutrophic conditions. Principal component analysis based on the diatom assemblages in temporal scale showed the response of diatoms succession to nutrients. Redundancy analysis also confirmed that nutrient enrichment was the main driving force for the succession of diatom assemblages in Lake Xihu, Dali. In the past 50 years, climate change and human activities (i.e., agricultural reclamation, fertilization, animal husbandry, and fishery) have enhanced the accumulation of nutrients in the lake. The continuous loading of nutrients promoted the propagation of planktonic algae, and also the productivity of the lake, rendering the transformation to a turbid phytoplankton-dominated state.

Clinical and sonographic features for the preoperative prediction of lymph nodes posterior to the right recurrent laryngeal nerve metastasis in patients with papillary thyroid carcinoma

OBJECTIVE

To evaluate clinical and sonographic features predictive of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in patients diagnosed with papillary thyroid carcinoma (PTC).

METHODS

We retrospectively reviewed the clinical records and ultrasound (US) images of 479 consecutive PTC patients who received total thyroidectomy or right lobectomy with central neck dissection (CND) between October 2017 and October 2019. Univariate and multivariate analyses were performed to identify clinical and sonographic features associated with LN-prRLN metastasis. Receiver operating characteristic (ROC) analysis was applied to evaluate the efficacy of clinical and sonographic features in the preoperative prediction of LN-prRLN metastasis.

RESULTS

Overall, 127 (26.5%) patients had LN-prRLN metastasis. Multivariate logistic regression analysis showed that age < 45 years (p = 0.005; OR 2.155; 95% CI 1.262-3.683), male sex (p = 0.043; OR 1.657; 95% CI 1.016-2.704), tumor diameter > 1 cm (p = 0.042; OR 1.702; 95% CI 1.019-2.842), microcalcifications (p = 0.022; OR 1.980; 95% CI 1.104-3.551), and US-detected lateral compartment lymph node (LLN) metastasis (p = 0.001; OR 2.578; 95% CI 1.500-4.430) were independent risk factors for LN-prRLN metastasis. ROC analysis revealed that the multivariate logistic regression model had good accuracy in predicting LN-prRLN metastasis, with an area under the ROC curve of 0.758.

CONCLUSIONS

Age less than 45 years, male sex, tumor diameter larger than 1 cm, microcalcifications, and US-detected LLN metastasis may preoperatively predict LN-prRLN metastasis.

Metoprolol rescues endothelial progenitor cell dysfunction in diabetes

Added risk portended by diabetes in addition to hypertension has been related to an amplification of endothelial dysfunction. β-blockers are widely used for cardiovascular diseases and improve the endothelial function compared with a placebo. However, the effect of β-blockers on the endothelial progenitor cells (EPCs) function in diabetes is still unknown. Five β-blockers (metoprolol, atenolol, propranolol, bisoprolol, and nebivolol) were tested in EPC functional screening. Metoprolol improved EPC function significantly among the five β-blockers and was chosen for the in vivo tests in STZ induced diabetic mice. Reactive hyperemia peripheral arterial tonometry (RH-PAT) measurements were performed using the Endo-PAT2000 device in diabetic patients. Metoprolol, but not other β-blockers, improved EPC function in both tube formation and migration assay. EPC function was significantly decreased in diabetic mice, and metoprolol treatment restored damaged EPC migration capabilities and circulation EPC number. Metoprolol treatment promoted wound healing and stimulated angiogenesis in diabetic mice. Furthermore, metoprolol significantly enhanced eNOS phosphorylation and decreased O₂⁻ levels in EPCs of diabetic mice. In clinical trials, the RH-PAT index was significantly higher in metoprolol-treated versus bisoprolol-treated diabetics. Metoprolol could accelerate wound healing in diabetic mice and improve endothelial function in diabetic subjects, which may be mediated in part by improving impaired EPC function.

Robust and nanostructured chitosan-silica hybrids for bone repair application

In this study, chitosan-silica hybrids (CSHs) with superior mechanical strength and homogeneous dispersion of nano-sized silica particles were synthesized via a facile sol-gel method aiming for bone regeneration. The effects of varied acidic conditions of sol-gel reaction and inorganic/organic ratios on the performance of the hybrid were investigated. CSHs synthesized under weak acidic conditions (acetic acid, pH 4.0) showed a homogeneous nanostructure and robust strength (maximum compressive strength: 42.6 ± 3.3 MPa and 271 ± 31 MPa in wet and dry forms, respectively). However, those developed under the strong acidic condition (HCl, pH 4.0) and the strong acid condition plus lower pH (HCl, pH 2.8) tended to aggregate and exhibited inferior mechanical properties (compressive strength: 6.3 ± 0.3 MPa in wet form at pH 2.8). Under the latter conditions, the interactions between silica and chitosan were weak. Moreover, the mechanical properties of the CSHs could be tuned in a wide range by conveniently varying the inorganic/organic composition ratio between 50% and 70%. In vitro cytocompatibility study indicated that CSHs were non-cytotoxic. These results suggested that the weak acidic sol-gel process were essential for fabricating chitosan-silica hybrids with high mechanical strength, which had potential to be applied as a bone substitute.

[Value of intravoxel incoherent motion diffusion weighted imaging in evaluating the microstructure changes in white matter hyperintensities]

Objective: To investigate the value of intravoxel incoherent motion diffusion weighted imaging (IVIM DWI) in evaluating microstructure changes in elderly white matter hyperintensities (WMH) patients and to analyze the correlation between IVIM parameters and severity grading and cognitive scores. Methods: Sixty-two WMH patients in Zhejiang Hospital were collected from December 2014 to March 2018 and underwent conventional magnetic resonance (MR) plain scan and diffusion weighted imaging with different b values. The age was 60-92(74±10) years with 37 males, 25 females. The severity of WMH was assessed by T(2) fluid attenuated inversion recovery (FLAIR) sequence and Fazekas score,which were divided into two subgroups. Slow diffusion coefficient (D), fast diffusion coefficient (D(*)) and perfusion fraction (f) from IVIM parameters of double exponential model were compared between regions of WMH (deep WMH (DWMH) and periventricular WMH (PWMH)) and surrounding normal white matter (NWM).The Shapiro-Wilk test was used for normality tests, Kruskal-Wallis tests and Dwass-Steel-Critchlow-Fligner (DSCF) procedure were used for the comparison among these parameters. Furthermore, Wilcoxon two-sample test was used for the comparisons between different severity. Pearson correlation analysis was performed to determine whether these D, D(*), f values were correlated with the mini mental state examination (MMSE) scores. Results: D(D)WMH (0.83(0.72,0.99)×10(-3) mm(2)/s), D(PWMH)((1.13±0.25)×10(-3) mm(2)/s) were significantly higher than D(NWM) ((0.71±0.05)×10(-3) mm(2)/s)(P<0.01). f (DWMH) ((8.94%(7.46%,11.67%)), f (PWMH)(8.34%(6.73%,9.96%)) were significantly higher than f (NWM)(6.71%±1.72%)(P<0.01).D in DWMH were significantly lower than that in PWMH(P<0.01), there's no statistically difference between other groups. D in severe WMH (both DWMH and PWMH) were significantly higher than that in mild WMH (P=0.000 1, P=0.04). Only f in PWMH were positively associated with the MMSE scores (r=0.326 5,P<0.05). Conclusions: IVIM DWI can noninvasively assess the variation of microstructure diffusion and perfusion in WMH in one sequence,which may objectively reflect the severity of these lesions. This method has important clinical significance for better assessment and management of this disease.

[Correlations between gastric Helicobacter pylori infection and colorectal polyps or cancer]

Objective: To investigate the correlations between gastric Helicobacter pylori (Hp) infection and colorectal polyps or cancer. Methods: Among patients who finished colonoscopy exams in Peking Union Medical College Hospital (PUMCH) between May 2012 and May 2017, 3 483 patients were diagnosed with colorectal polyps, 135 patients with newly diagnosed colorectal cancer. A total of 1 925 healthy subjects were enrolled as normal controls. Gastric rapid urease tests (RUT) were done in all patients. General clinical data, RUT results, sizes and numbers of polyps, cancer location were analyzed. Results: The proportion of Hp infection in patients with colorectal polyps was 31.5%, higher than that in healthy controls. The odds ratio (OR) of Hp infection in polyp group was 1.17 (95%CI 1.04-1.32) after age and gender were adjusted. The Hp infection rate in patients with polyps over or equal to 1 cm was significantly higher than that in patients with polyps smaller than 1 cm. Patients with more than 1 polyps presented a higher rate of Hp infection than patients with only 1 polyp. Hp infection rate in patients with colorectal cancer was 36.3%, with the adjusted OR 1.56 (95%CI 1.06-2.30). The location of colorectal cancer was not correlated with Hp infection. Conclusions: Gastric Hp infection is more common in patients with colorectal polyps than in healthy controls. Polyps ≥1 cm, multiple polyps and colorectal cancer are correlated with higher rates of Hp infection. Cancer location is irrelevant to Hp infection.

[Prevalence and influential factors of stroke in Jiangxi Province in 2014]

Objective: To discuss the prevalence and influential factors of stroke among population in Jiangxi Province. Methods: Four cities in urban areas and four counties in rural areas were selected firstly, in which two districts or townships were selected; and then three communities or villages were chosen from each district and township, respectively, using the simple random sampling (SRS) method. Finally 15 269 subjects aging 15 years old or above, living in Jiangxi Province ≥6 months were randomly selected to participate in this survey from November 2013 to August 2014. Information of population characteristics, life behavior way, individual disease history were collected through questionnaire survey, and height, weight, waist circumference, blood pressure, body fat rate, visceral fat index and so on were measured by instruments. Risk factors of stroke prevalence were analyzed by the unconditioned logistic regression analysis. Results: A total of 15 269 participants (6 267 males) from 15 364 eligible participants were included in the statistical analysis. Out of which, 7 793 participants came from urban areas, and their average age was (53.04±17.91) years old. In this study, 226 stroke patients (117 males) were found among15 269 participants, including 122 urban participants and 104 rural participants, whose average age was (67.76±9.74) years old. The prevalence of stroke was 1 480.12/100 000 in 2014, which was separately 1 866.92/100 000 and 1 210.84/100 000 among males and females. The prevalence of people aging (45-49) years old was 413.79/100 000 (6/1 450) , while which among people aging 75 years old and above was 3 311.62/100 000 (61/1 842) . The prevalence of stroke among residents in Jiangxi presented an uprising tendency with age increasing (linear-by-linear association χ(2)=62.23, P<0.01). The research showed that when other influencing factors including gender, BMI, waist circumference, pulse-pressure difference, VAI, and sleeping time in non-working days were controlled, hypertensive patients had a higher risk of stroke than people without hypertension (OR=6.88, 95%CI: 4.90-9.67), drinkers had a higher risk of stroke than non-drinkers (OR=1.56, 95%CI: 1.17-2.08), compared with people <65 years old, people aged 65-74 years old and ≥75 years old had a higher risk of stroke, the value of OR (95%CI) were 1.88 (1.36-2.59) and 1.97 (1.39-2.80), respectively, compared with people with normal body fat percentage, people whose body fat percentage on high side and people who with high body fat percentage had a higher risk of stroke, the value of OR (95%CI) were 1.71 (1.18-2.48) and 1.74 (1.18-2.56), respectively, people with sleep time >8 h had a higher risk of stroke than those with sleep time of 6-8 h. Conclusion: There was a high stroke prevalence among residents in Jiangxi province. Hypertension, drinking, age, BFP and sleep duration were associated with stroke prevalence. Corresponding measures for high-risk population and risk factors should be strengthened to prevent and control the stroke.

[Near infrared distance sensing method for Chang'e-3 alpha particle X-ray spectrometer]

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover, the scientific objective of which is in-situ observation and off-line analysis of lunar regolith and rock. Distance measurement is one of the important functions for APXS to perform effective detection on the moon. The present paper will first give a brief introduction to APXS, and then analyze the specific requirements and constraints to realize distance measurement, at last present a new near infrared distance sensing algorithm by using the inflection point of response curve. The theoretical analysis and the experiment results verify the feasibility of this algorithm. Although the theoretical analysis shows that this method is not sensitive to the operating temperature and reflectance of the lunar surface, the solar infrared radiant intensity may make photosensor saturation. The solutions are reducing the gain of device and avoiding direct exposure to sun light.

Co-transfection of adeno-associated virus-mediated human vascular endothelial growth factor165 and transforming growth factor-β1 into annulus fibrosus cells of rabbit degenerative intervertebral discs

Intervertebral disc degeneration is a common condition that may lead to low back pain and radiculopathy. Understanding the pathophysiology and cellular and molecular events of degenerative disc disease has resulted in the proposal of a gene therapy approach to halt and reverse disc degeneration. We explored the feasibility of reversing intervertebral disc degeneration using human vascular endothelial growth factor165 (hVEGF165) and transforming growth factor-β1 (TGF-β1) gene therapy. hVEGF165 complementary DNA was obtained from pcDNA3(+)-hVEGF165 and cloned into adeno-associated virus (AAV)-pSNAV plasmids to construct the recombinant plasmid, AAV-pSNAV-hVEGF165. After identification through restriction enzyme digestion and DNA sequencing, the AAV-pSNAV-hVEGF165 was transfected into HEK293 cells and vascular endothelial cells. Protein expression of hVEGF165 was detected using a fluorescent immunohistochemical assay, and the effect of hVEGF165 on vascular endothelial cell proliferation was determined with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Packaged AAV-hVEGF165 and AAV-TGF-β1 were co-transfected into the annulus fibrosus cells of degenerative intervertebral discs. hVEGF165 and TGF-β1 expression by annulus fibrosus cells and the effect of the co-transfection on the level of collagen type I protein expression by annulus fibrosus cells were detected with Western blot. The results of restriction enzyme digestion and DNA sequencing confirmed that AAV-pSNAV-hVEGF165 plasmids were constructed. The fluorescent immunohistochemical results confirmed hVEGF165 protein expression. The MTT results showed that the hVEGF165 protein promoted vascular endothelial cell proliferation. Biologically active AAV-hVEGF165 and AAV-TGF-β1 were successfully constructed. Western blot confirmed hVEGF165 and TGF-β1 expression in annulus fibrosus cells and demonstrated that the level of collagen type I protein expression was significantly higher in annulus fibrosus cells co-transfected with both AAV-hVEGF165 and AAV-TGF-β1 compared with that in cells transfected with AAV-hVEGF165 or AAV-TGF-β1 alone. hVEGF165 has a synergistic effect with TGF-β1 that promotes the expression of collagen type I protein in annulus fibrosus cells from degenerative intervertebral discs.

[Temperature effect correction for Chang'E-3 alpha particle X-ray spectrometer]

Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover of China's Lunar Exploration Project. The present paper introduces briefly the components of APXS, how it works and its working environment on the lunar surface. The environmental temperature effect has been studied with simulations and experiments, and the results show that the temperature of the APXS sensor will be varying during the measuring on the lunar surface. And another experiment reveals that the energy resolution becomes worse if the sensor's temperature is varying. In this paper, a correction method based on Pearson's chi-squared test is presented. The method can improve the energy resolution when the sensor's temperature is varying. We have tested the method with the spectra acquired by APXS in the temperature varying period of Temperature Cycling Test, and the results show that the method is efficient and reliable.

[Antioxidant activity and spectroscopic behavior study with DNA of several Salen Mn(II), Eu(III) complexes]

Five kinds of Salen Mn(II) and two kinds of Eu(III) complexes were synthesized. Under the system of NBT/L-methionine, which creates and detects O2*-, the complexes of antioxidant activity were studied, and the conclusion revealed that all Mn(II) complexes have obvious antioxidant activity. The fluorescence study indicated that all the Salen metal complexes could bind with DNA, which shows their potential anticancer activity.

Aliskiren prevents cardiovascular complications and pancreatic injury in a mouse model of obesity and type 2 diabetes

AIMS/HYPOTHESIS

The effect of renin inhibition on type 2 diabetes is still unclear. The present study was undertaken to examine the efficacy of aliskiren, a direct renin inhibitor, on cardiovascular injuries, glucose intolerance and pancreatic injury in a mouse model of type 2 diabetes.

METHODS

Groups of db/db mice, with obesity and type 2 diabetes, were treated with aliskiren (3, 6, 12 and 25 mg kg(-1) day(-1)) or hydralazine (80 mg kg(-1) day(-1)) for 6 weeks, and the protective effects were extensively compared among groups.

RESULTS

All sub-pressor and hypotensive doses of aliskiren significantly attenuated cardiac fibrosis, macrophage infiltration and coronary remodelling, and improved vascular endothelial function in db/db mice. These protective effects of aliskiren were attributed to the attenuation of cardiac p22(phox)-related NADPH oxidase-induced superoxide and the restoration of vascular endothelial nitric oxide synthase (eNOS) production. Aliskiren at the highest dose (25 mg kg(-1) day(-1)), but not at lower doses, partially reduced glucose intolerance in db/db mice. Furthermore, the highest dose of aliskiren significantly attenuated the decreases in pancreatic islet insulin content and beta cell mass, and prevented pancreatic islet fibrosis in db/db mice, being associated with the reduction of 8-hydroxy-2'-deoxyguanosine-positive cells and Nox2 (also known as Cybb) expression in pancreatic islets by aliskiren.

CONCLUSIONS/INTERPRETATION

Our work provides the first evidence that direct renin inhibition with aliskiren protects against cardiovascular complications and pancreatic injury, through the attenuation of oxidative stress. Thus, we propose that aliskiren may be a promising therapeutic agent for type 2 diabetes.

Morphine applied to the thalamic nucleus submedius produces a naloxone reversible antinociceptive effect in the rat

Our previous studies have indicated that the thalamic nucleus submedius (Sm) is involved in nociceptive modulation and plays an important role in an endogenous analgesic system (a feedback loop) consisting of spinal cord - Sm - ventrolateral orbital cortex (VLO) - periaqueductal gray (PAG) - spinal cord. To further investigate the neurotransmitter and receptor mechanisms in this nociceptive modulatory pathway, we tested the effects of microinjection of morphine and naloxone into the Sm on the rat tail flick (TF) reflex. A unilateral microinjection of morphine (8.0 mM, 0.5 microl) into the Sm significantly depressed the TF reflex, whereas a unilateral microinjection of naloxone (5.0 mM, 0.5 microl) into the Sm facilitated the TF reflex. Five minutes after morphine application into Sm, injection of naloxone in this nucleus markedly reversed the inhibition evoked by applying morphine in Sm. These findings suggest that the endogenous opioid peptides may be involved in the antinociceptive effects evoked by activation of the Sm-VLO-PAG pathway which depressed the nociceptive inputs at the spinal level via the brainstem descending inhibitory system, and exert a tonic descending influence.