The ciliary protein Spef2 stimulates acinar Ampkα/Sirt1 signaling and ameliorates acute pancreatitis and associated lung injury.

Background: Pancreatic acinar cells are susceptible to nuclear factor kappa B (NF-κB)-mediated inflammation and resulting cell necrosis during early acute pancreatitis. As adenosine monophosphate-activated protein kinase alpha (Ampkα)/sirtuin 1 (Sirt1) pathway activity attenuates NF-κB activity, we examined whether the Ampkα/Sirt1 axis affects the progression of acute pancreatitis and associated lung injury in vivo. Furthermore, we explored the role of the ciliary protein sperm flagellar 2 (Spef2, Kpl2) in regulating Ampkα/Sirt1 activity in vitro and in vivo. Methods: Pancreatic injury, oxidative stress, acinar cell necrosis and apoptosis, acinar levels of Ampkα/Sirt1/NF-κB signaling activity, NF-kB-mediated inflammatory markers, and markers of associated lung injury were measured in rat models of acute pancreatitis following pharmacological Ampkα activation with A769662 or self-complementary recombinant adeno-associated virus serotype 6 (scAAV6)-mediated Spef2 overexpression. Additional in vivo rescue studies involving Ampkα silencing and/or constitutively active (CA)-Sirt1 overexpression were performed in acute pancreatitis rats. In vitro immunoblotting and Ampkα activity assays were conducted in the pancreatic acinar cell line AR42J. Results: Pharmacological Ampkα activation or Spef2 overexpression reduced acute pancreatitis severity, oxidative stress, necrosis, apoptosis, NF-kB-mediated inflammatory markers, and the degree of associated lung injury. Spef2 overexpression in AR42J cells in vitro promoted AmpkαThr172 phosphorylation and Ampkα activity. In vivo rescue studies revealed that Spef2's suppressive effect on acute pancreatitis and associated lung injury is mediated via the Ampkα/Sirt1 axis. Conclusions: This study established the existence of a Spef2/Ampkα/Sirt1 axis in pancreatic acinar cells that is involved in the regulation of NF-κB-mediated acinar cell inflammation and resulting cell necrosis during acute pancreatitis.

Synthesis of Chiral Endocyclic Allenes by Palladium-Catalyzed Asymmetric Annulation Followed by Cope Rearrangement.

Catalytic asymmetric synthesis of chiral endocyclic allenes remains a challenge in allene chemistry owing to unfavored tension and complex chirality. Here, we present a new relay strategy merging Pd-catalyzed asymmetric [3+2] annulation with enyne-Cope rearrangement, providing a facile route to chiral 9-membered endocyclic allenes with high efficiency and enantioselectivity. Moreover, theoretical calculations and experimental studies were performed to illustrate the critical, but unusual Cope rearrangement that allows for the complete central-to-axial chirality transfer.

The accuracy and effectiveness of automatic pedicle screw trajectory planning based on computer tomography values: an in vitro osteoporosis model study.

BACKGROUND: Pedicle screw placement in patients with osteoporosis is a serious clinical challenge. The bone mineral density (BMD) of the screw trajectory has been positively correlated with the screw pull-out force, while the computer tomography (CT) value has been linearly correlated with the BMD. The purpose of this study was to establish an in vitro osteoporosis model and verify the accuracy and effectiveness of automated pedicle screw planning software based on CT values in this model. METHODS: Ten vertebrae (L1-L5) of normal adult pigs were randomly divided into decalcification and control groups. In the decalcification group, the vertebral bodies were decalcified with Ethylenediaminetetraacetic acid (EDTA) to construct an in vitro osteoporosis model. In the decalcification group, automatic planning (AP) and conventional manual planning (MP) were used to plan the pedicle screw trajectory on the left and right sides of the pedicle, respectively, and MP was used on both sides of the control group. CT values of trajectories obtained by the two methods were measured and compared. Then, 3D-printed guide plates were designed to assist pedicle screw placement. Finally, the pull-out force of the trajectory obtained by the two methods was measured. RESULTS: After decalcification, the BMD of the vertebra decreased from - 0.03 ± 1.03 to - 3.03 ± 0.29 (P < 0.05). In the decalcification group, the MP trajectory CT value was 2167.28 ± 65.62 Hu, the AP trajectory CT value was 2723.96 ± 165.83 Hu, and the MP trajectory CT value in the control group was 2242.94 ± 25.80 Hu (P < 0.05). In the decalcified vertebrae, the screw pull-out force of the MP group was 48.6% lower than that of the control group (P < 0.05). The pull-out force of the AP trajectory was 44.7% higher than that of the MP trajectory (P < 0.05) and reached 97.4% of the MP trajectory in the control group (P > 0.05). CONCLUSION: Automatic planning of the pedicle screw trajectory based on the CT value can obtain a higher screw pull-out force, which is a valuable new method of pedicle screw placement in osteoporotic vertebre.

Does MIS-TLIF or TLIF result in better pedicle screw placement accuracy and clinical outcomes with navigation guidance?

BACKGROUND: Although previous studies have suggested that navigation can improve the accuracy of pedicle screw placement, few studies have compared navigation-assisted transforaminal lumbar interbody fusion (TLIF) and navigation-assisted minimally invasive TLIF (MIS-TLIF). The entry point of pedicle screw insertion in navigation-assisted MIS-TLIF (NM-TLIF) may deviate from the planned entry point due to an uneven bone surface, which may result in misplacement. The purpose of this study was to explore the pedicle screw accuracy and clinical consequences of MIS-TLIF and TLIF, both under O-arm navigation, to determine which surgical method is better. METHODS: A retrospective study of 54 patients who underwent single-segment NM-TLIF or navigation-assisted TLIF (N-TLIF) was conducted. In addition to the patients' demographic characteristics, intraoperative indicators and complications, the Oswestry Disability Index (ODI) and visual analog scale (VAS) score were recorded and analyzed preoperatively and at the 1-, 6-, and 12-month and final postoperative follow-ups. The clinical qualitative accuracy and absolute quantitative accuracy of pedicle screw placement were assessed by postoperative CT. Multifidus muscle injury was evaluated by T2-weighted MRI. RESULTS: Compared with N-TLIF, NM-TLIF was more advantageous in terms of the incision length, intraoperative blood loss, drainage volume, time to ambulation, length of hospital stay, blood transfusion rate and analgesia rate (P < 0.05). The ODI and VAS scores for low back pain were better than those of N-TLIF at 1 month and 6 months post-surgery (P < 0.05). There was no significant difference in the clinical qualitative screw placement accuracy (97.3% vs. 96.2%, P > 0.05). The absolute quantitative accuracy results showed that the axial translational error, sagittal translational error, and sagittal angle error in the NM-TLIF group were significantly greater than those in the N-TLIF group (P < 0.05). The mean T2-weighted signal intensity of the multifidus muscle in the NM-TLIF group was significantly lower than that in the N-TLIF group (P < 0.05). CONCLUSIONS: Compared with N-TLIF, NM-TLIF has the advantages of being less invasive, yielding similar or better screw placement accuracy and achieving better symptom relief in the midterm postoperative recovery period. However, more attention should be given to real-time adjustment for pedicle insertion in NM-TLIF rather than just following the entry point and trajectory of the intraoperative plan.

Duodenal microbiota makes an important impact in functional dyspepsia.

Duodenal microbiota may have impact in Functional Dyspepsia. The aim of this study was to explore the difference of microbiota on duodenal mucosa between patients with Functional Dyspepsia and normal subjects. The duodenal mucosa of the subjects were collected under upper gastrointestinal endoscope and the contents of the descending duodenal intestine were extracted with cell brushes in 20 patients with Functional Dyspepsia and 5 healthy subjects. The microbiome on duodenal was studied by 16SrDNA gene sequencing. The differences of duodenal flora were analyzed and compared by LEfSe, FAPROTAX, SPSS and other software. There were significant differences in ACE index, shannon index and observedspecies index between patients with functional dyspepsia and healthy people (P < 0.05). PCoA analysis of the structure of bacteria between two groups found that the duodenal microbiome showed a separate trend. In further study, Amova analysis showed a significant difference (P < 0.05). We found that the there are obvious differences in the composition of duodenal microbiome in functional dyspepsia and healthy people. At the genus level, there were significant differences in Alloprevotella, Peptostreptococcus,Sutterella, Corynebacteriurn,Catonella, Faecalibacterium,Staphylococcus,Eubacteriumnodatumgro-up, Lachnoclostridiurn and Lautropia between the two groups (P < 0.05). The prediction results of Microflora function from FAPROTAX showed that the urea decomposing (ureolysis) and fumaric acid respiratory (fumaraterespiration) function of duodenal bacteria in patients with functional dyspepsia were significantly different from those in healthy people (P < 0.05). In conclusion, there is a significant difference in mucosal microflora of duodenum between patients with functional dyspepsia and healthy groups. It includes greater microflora diversity, different microflora structure, different microflora composition, specific taxa and specific microbiome function. The disorder of duodenal microecology may be the formation mechanism of functional dyspepsia.

UV and visible light photocatalytic activity of Au/TiO2 nanoforests with Anatase/Rutile phase junctions and controlled Au locations.

To magnify anatase/rutile phase junction effects through appropriate Au decorations, a facile solution-based approach was developed to synthesize Au/TiO2 nanoforests with controlled Au locations. The nanoforests cons®isted of anatase nanowires surrounded by radially grown rutile branches, on which Au nanoparticles were deposited with preferred locations controlled by simply altering the order of the fabrication step. The Au-decoration increased the photocatalytic activity under the illumination of either UV or visible light, because of the beneficial effects of either electron trapping or localized surface plasmon resonance (LSPR). Gold nanoparticles located preferably at the interface of anatase/rutile led to a further enhanced photocatalytic activity. The appropriate distributions of Au nanoparticles magnify the beneficial effects arising from the anatase/rutile phase junctions when illuminated by UV light. Under the visible light illumination, the LSPR effect followed by the consecutive electron transfer explains the enhanced photocatalysis. This study provides a facile route to control locations of gold nanoparticles in one-dimensional nanostructured arrays of multiple-phases semiconductors for achieving a further increased photocatalytic activity.

[Parameters modification and evaluation of two evapotranspiration models based on Penman-Monteith model for summer maize]. / 基于Penman-Monteith模型的两个蒸散模型在夏玉米农田的参数修正及性能评价.

The dynamic variations of evapotranspiration (ET) and weather data during summer maize growing season in 2013-2015 were monitored with eddy covariance system, and the applicability of two operational models (FAO-PM model and KP-PM model) based on the Penman-Monteith model were analyzed. Firstly, the key parameters in the two models were calibrated with the measured data in 2013 and 2014; secondly, the daily ET in 2015 calculated by the FAO-PM model and KP-PM model was compared to the observed ET, respectively. Finally, the coefficients in the KP-PM model were further revised with the coefficients calculated according to the different growth stages, and the performance of the revised KP-PM model was also evaluated. These statistical parameters indicated that the calculated daily ET for 2015 by the FAO-PM model was closer to the observed ET than that by the KP-PM model. The daily ET calculated from the revised KP-PM model for daily ET was more accurate than that from the FAO-PM model. It was also found that the key parameters in the two models were correlated with weather conditions, so the calibration was necessary before using the models to predict the ET. The above results could provide some guidelines on predicting ET with the two models.

Effect of vegetation rehabilitation on soil carbon and its fractions in Mu Us Desert, northwest China.

Although vegetation rehabilitation on semi-arid and arid regions may enhance soil carbon sequestration, its effects on soil carbon fractions remain uncertain. We carried out a study after planting Artemisia ordosica (AO, 17 years), Astragalus mongolicum (AM, 5 years), and Salix psammophila (SP, 16 years) on shifting sand land (SL) in the Mu Us Desert, northwest China. We measured total soil carbon (TSC) and its components, soil inorganic carbon (SIC) and soil organic carbon (SOC), as well as the light and heavy fractions within soil organic carbon (LF-SOC and HF-SOC), under the SL and shrublands at depths of 100 cm. TSC stock under SL was 27.6 Mg ha(-1), and vegetation rehabilitation remarkably elevated it by 40.6 Mgha(-1), 4.5 Mgha(-1), and 14.1 Mgha(-1) under AO, AM and SP land, respectively. Among the newly formed TSC under the three shrublands, SIC, LF-SOC and HF-SOC accounted for 75.0%, 10.7% and 13.1% for AO, respectively; they made up 37.0%, 50.7% and 10.6% for AM, respectively; they occupied 68.6%, 18.8% and 10.0% for SP, respectively. The accumulation rates of TSC within 0-100 cm reached 238.6 g m(-2) y(-1), 89.9 g m(-2) y(-1) and 87.9 g m(-2) y(-1) under AO, AM and SP land, respectively. The present study proved that the accumulation of SIC considerably contributed to soil carbon sequestration, and vegetation rehabilitation on shifting sand land has a great potential for soil carbon sequestration.

MYC regulation of CHK1 and CHK2 promotes radioresistance in a stem cell-like population of nasopharyngeal carcinoma cells.

Radiotherapy is the most successful nonsurgical treatment for nasopharyngeal carcinoma (NPC). Despite this, the prognosis remains poor. Although NPCs initially respond well to a full course of radiation, recurrence is frequent. The cancer stem cell (CSC) hypothesis provides a framework for explaining the discrepancy between the response of NPC to therapy and the poor survival rate. In this study, a stem cell-like subpopulation (PKH26+) was identified in NPC cell lines using a label-retention technique. PKH26+ cells were enriched for clonogenicity, sphere formation, side-population cells, and resistance to radiotherapy. Using genomic approaches, we show that the proto-oncogene c-MYC (MYC) regulates radiotolerance through transcriptional activation of CHK1 (CHEK1) and CHK2 (CHEK2) checkpoint kinases through direct binding to the CHK1 and CHK2 promoters. Overexpression of c-MYC in the PKH26+ subpopulation leads to increased expression of CHK1 and CHK2 and subsequent activation of the DNA-damage-checkpoint response, resulting in radioresistance. Furthermore, loss of CHK1 and CHK2 expression reverses radioresistance in PKH26+ (c-MYC high expression) cells in vitro and in vivo. This study elucidates the role of the c-MYC-CHK1/CHK2 axis in regulating DNA-damage-checkpoint responses and stem cell characteristics in the PKH26+ subpopulation. Furthermore, these data reveal a potential therapeutic application in reversal of radioresistance through inhibition of the c-MYC-CHK1/CHK2 pathway.

Influence of disturbance on soil respiration in biologically crusted soil during the dry season.

Soil respiration (Rs) is a major pathway for carbon cycling and is a complex process involving abiotic and biotic factors. Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. In desert ecosystems, soils are protected from surface disturbance by BSCs, but it is unknown whether Rs is affected by disturbance of this crust layer. We measured Rs in three types of disturbed and undisturbed crusted soils (algae, lichen, and moss), as well as bare land from April to August, 2010, in Mu Us desert, northwest China. Rs was similar among undisturbed soils but increased significantly in disturbed moss and algae crusted soils. The variation of Rs in undisturbed and disturbed soil was related to soil bulk density. Disturbance also led to changes in soil organic carbon and fine particles contents, including declines of 60-70% in surface soil C and N, relative to predisturbance values. Once BSCs were disturbed, Q 10 increased. Our findings indicate that a loss of BSCs cover will lead to greater soil C loss through respiration. Given these results, understanding the disturbance sensitivity impact on Rs could be helpful to modify soil management practices which promote carbon sequestration.

[B-mode ultrasound for defining planning target volume in intensity-modulated radiotherapy for prostate cancer].

OBJECTIVE: To define the planning target volume (PTV) margins in intensity-modulated radiotherapy (IMRT) for prostate cancer without imaging guidance using B-mode acquisition and targeting (BAT) ultrasound-based prostate localization. METHODS: Ten patients with prostate cancer underwent BAT ultrasound alignment before each IMRT session. The set-up deviations, each consisting of isocenter displacements in 3 directions (anterior-posterior, right-left lateral, and superior-inferior), were recorded for a total of 225 times and analyzed with Kolmogorov-Smimov (K-S) method. RESULTS: The isocenter shift in each direction, which represented an average from all the patients, was 3.56∓2.71 mm, 4.08∓3.99 mm, and 3.20∓2.92 mm in the lateral (RL), anteroposterior (AP), and superior-inferior (SI) dimensions, respectively, and the deviations in each direction conformed to a normal distribution (P=0.806, P=0.061, and P=0.106, respectively). In the absence of imaging guidance for IMRT for prostate cancer, the PTV margin should expand by 8.97 mm in the right, 1.87 mm in the left, 12.05 mm in the anterior, 3.91 mm in the posterior, 9.06 mm in the superior and 2.66 mm in the inferior to allow 95% isodose curve to cover 90% of the clinical target volume. CONCLUSION: The ultrasound imagining guided localization, with simple operation, nonirradiation and small systemic error, can be real-time corrected.

[Determination of the repair half-time of human nasopharyngeal carcinoma cell lines CNE1, CNE2, HONE1 and C666-1].

OBJECTIVE: To determine the repair half-time (T1/2), a speed parameter of sub-lethal damage repair (SLDR), of human nasopharyngeal carcinoma (NPC) cell lines CNE1, HONE1, C666-1 and CNE2. METHODS: A total radiation dose of 8 Gy divided into 4+4 Gy was delivered to the cell lines at the interval of 0 s, 15 s, 30 s, 1 h, 2 h, 4 h or 6 h. The cell survival fractions were determined using the standard cell clonogenic assay. The curves of the changes in the surviving cell fraction after a total dose of 8 Gy, as a function of the interval between the two doses of 4 Gy, were fitted manually, and the T1/2 of each cell line was calculated according to the curves. RESULTS: The T1/2 of CNE1, HONE1, C666-1 and CNE2 were 18 s, 22 s, 29 s and 27 s, respectively. CONCLUSION: The speed of SLDR of NPC cells is quite rapid, indicating that the fraction delivery time longer than 20 s might decrease the effect of radiotherapy.