Environmental drivers of increased ecosystem respiration in a warming tundra

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.

Observation of WWγ Production and Search for Hγ Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The observation of WWγ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138  fb^{-1} is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WWγ is 5.9±0.8(stat)±0.8(syst)±0.7(modeling)  fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.

Mendelian randomization and colocalization analyses reveal an association between short sleep duration or morning chronotype and altered leukocyte telomere length

Observational studies suggest certain sleep traits are associated with telomere length, but the causal nature of these associations is unclear. The study aimed to determine the causal associations between 11 sleep-related traits and leukocyte telomere length (LTL) through two-sample Mendelian randomization and colocalization analyses using the summary statistics from large-scale genome-wide association studies. Univariable Mendelian randomization indicates that genetically determined short sleep is associated with decreased LTL, while morning chronotype is associated with increased LTL. Multivariable Mendelian randomization further supports the findings and colocalization analysis identifies shared common genetic variants for these two associations. No genetic evidence is observed for associations between other sleep-related traits and LTL. Sensitivity MR methods, reverse MR and re-running MR after removing potential pleiotropic genetic variants enhance the robustness of the results. These findings indicate that prioritizing morning chronotype and avoiding short sleep is beneficial for attenuating telomere attrition. Consequently, addressing sleep duration and chronotype could serve as practical intervention strategies.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

AB0156 INTRA-ARTICULAR AGRIN PROVIDES DIRECT PAIN RELIEF IN OSTEOARTHRITIS AND CARTILAGE DEFECTS

Background

Osteoarthritis is the leading cause of disability worldwide with a financial burden estimated between 1.5 and 2% of the GDP in all westernised countries. The main driver of progression in osteoarthritis is cartilage loss, which may be associated with bone changes, low degree synovitis and lesions to menisci and ligaments. These pathological features result in pain, which contributes to chronic disability.

Improving cartilage integrity without pain relief does not help patients and results in failure in clinical trials. Therefore, there is a need for therapeutics that induce rapid pain relief and long-term cartilage regeneration.

We previously showed that Agrin results in cartilage regeneration and in this study, following on the serendipitous finding of rapid pain relief after Agrin administration we explore its analgesic effect in animal models of osteochondral defects and osteoarthritis.

Objectives

Test the analgesic potential of Agrin in post-surgical pain associated with osteochondral defects in mice and sheep.

Determine whether Agrin can relieve chronic pain induced by osteoarthritis in mice.

Investigate the therapeutic potential of Agrin in models of primary and injury-induced secondary osteoarthritis.

Methods

Acute post-surgical pain: Surgery was performed on skeletally mature male mice and female sheep to create critical-sized osteochondral defects; defects were filled with collagen gel containing PBS or Agrin. Animals were sacrificed 8 weeks (mice) and 6 months (sheep) after surgery. Pain was measured in mice using von Frey filaments and incapacitance readings. Sheep were fitted with accelerometers for the duration of the study.

Osteoarthritic pain: Osteoarthritis was surgically induced in skeletally mature male mice by menisco-ligament injury (MLI). Control mice received sham surgery. Nine weeks post-surgery, once chronic pain was established, mice were injected intra-articularly with recombinant Agrin. Pain was measured by von Frey filaments and incapacitance.

Treatment in therapeutic regime: Tamoxifen-inducible transgenic mice overexpressing Agrin under the AggrecanCre promotor were generated. Skeletally mature male mice were subjected to menisco-ligament injury surgery. Four weeks later, tamoxifen was administered to overexpress Agrin in the cartilage. Pain was measured by von Frey filaments and incapacitance.

Ex-vivo: MicroCT, X-ray, Kellgren-Laurence scoring, histology, OARSI scoring and immunohistochemistry.

Results

In sheep, Agrin administration induced regeneration in osteochondral defects and, more importantly, reduced the levels of secondary osteoarthritis. This was associated with a rapid and sustained symptomatic relief.

In mice, Agrin expression was lost in the dorsal root ganglia corresponding to the limb subjected to MLI but not in the dorsal root ganglia corresponding to the sham operated limbs.

Intra-articular recombinant Agrin in mice with established OA (9 weeks after MLI surgery) resulted in pain relief as early as three hours after administration. Acute administration of recombinant Agrin does not have any analgesic effects in sham operated mice.

Inducible, cartilage-specific Agrin-overexpression mice were protected from developing pain associated with instability-induced osteoarthritis.

In mice with acute osteochondral defects, intra-articular Agrin administration resulted in pain relief for at least five days.

In humans, the loss of Agrin in the articular cartilage correlated significantly with the Mankin score of patients undergoing knee replacement surgery.

Conclusion

Agrin has analgesic properties in both the acute phases of cartilage damage and in established osteoarthritis. Our findings support the therapeutic use of Agrin for joint surface regeneration and pain relief.

Disclosure of Interests

Suzanne Eldridge: None declared, Aida Barawi: None declared, Anne-Sophie Thorup: None declared, Beatriz F Fernandez: None declared, Sabah Bharde: None declared, Shafaq Sikandar: None declared, Zeyu Guan: None declared, Magdalena Kaneva: None declared, Helen Lydon: None declared, Fran Henson: None declared, Cosimo De Bari: None declared, Andrew McCaskie: None declared, Francesco Dell’Accio Consultant of: Prof Dell’Accio has consulted for Samumed, Grant/research support from: A PhD studentship unrelated to this abstract is funded by UCB

AB0039 AGRIN REPAIRS BONE AND CARTILAGE IN VIVO

Background:

Cartilage defects in the joints are reported in 61% of all arthroscopies1&2. The size of the cartilage repair market is estimated to be $2.195 million by 20253. Cartilage defects can evolve into osteoarthritis, in which abnormal load results in cartilage breakdown, joint pain and reduced mobility. Osteoarthritis is the leading cause of permanent disability and absenteeism and affects up to 1/3 of the people over 60yrs. In western countries osteoarthritis costs 1.5-2% of the GDP4. Joint replacement with a prosthesis restores some degree of independence but in up to 20% of patients it does not meet expectations 5 and has a limited life span. There is no pharmacological intervention that arrests or reverts the course of osteoarthritis, despite the desperate need.

We previously published that agrin plays an important role in cartilage homeostasis6. The addition of agrin to chondrocytes in vivo resulted in enhanced cartilage formation, suggesting a potential role for agrin in cartilage repair.

Objectives:

Investigate the potential of agrin for use in cartilage repair.

Methods:

Critical size osteochondral defects were generated in mice and sheep and injected intraarticularly with type I collagen gel containing agrin or vehicle. Animals were monitored for 8 weeks or 6 months respectively. MicroCT, histological analysis, qPCR, linage tracking, reporter assays, chondrogenesis assay, immunohistochemistry were performed.

Results:

A single intraarticular administration of agrin induced regeneration of critical-size osteochondral defects in mice, restoring the tissue architecture and bone-cartilage interface. Agrin stem cells to the site of injury and, through simultaneous activation of CREB and suppression of canonical WNT signalling, induced GDF5 expression and differentiation into stable articular chondrocytes, forming stable articular cartilage. In sheep, agrin treatment resulted in regeneration of bone and cartilage, which promoted increased ambulatory activity.

Conclusion:

Agrin orchestrates repair morphogenesis at the joint surface by modulating multiple signalling pathways, supporting the therapeutic use of agrin for joint surface regeneration.

References:

[1]Curl, W. W. et al. Cartilage injuries: a review of 31,516 knee arthroscopies. Arthrosc. J. Arthrosc. Relat. Surg. Off. Publ. Arthrosc. Assoc. N. Am. Int. Arthrosc. Assoc. 13, 456–460 (1997).

[2]Hjelle, K., Solheim, E., Strand, T., Muri, R. & Brittberg, M. Articular cartilage defects in 1,000 knee arthroscopies. Arthrosc. J. Arthrosc. Relat. Surg. Off. Publ. Arthrosc. Assoc. N. Am. Int. Arthrosc. Assoc. 18, 730–734 (2002).

[3]Cartilage Repair Market Size, Share, Industry Analysis 2018-2025 | AMR. Allied Market Research https://www.alliedmarketresearch.com/cartilage-repair-market.

[4]Hiligsmann, M. et al. Health economics in the field of osteoarthritis: an expert’s consensus paper from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). Semin. Arthritis Rheum. 43, 303–313 (2013).

[5]Dieppe, P., Lim, K. & Lohmander, S. Who should have knee joint replacement surgery for osteoarthritis? Int. J. Rheum. Dis. 14, 175–180 (2011).

[6]Eldridge, S., et al. Agrin mediates chondrocyte homeostasis and requires both LRP4 and α-dystroglycan to enhance cartilage formation in vitro and in vivo. Annals of the rheumatic diseases 75 (6), 1228-1235 (2016).

Acknowledgements:

We thank the technical staff in the ARM Lab and Staff at the University of Aberdeen’s Animal Facility and Microscopy and Histology Facility for support. Funding: We gratefully acknowledge funding support of this work by the MRC (MR/L022893/1, MR/N010973/1,and MR/P026362/1), Versus Arthritis (19667, 21515, 20886, and 21621), Rosetrees Trust (A1205), the Medical College of St Bartholomew’s Hospital Trust, and the William Harvey Research Foundation.

Disclosure of Interests:

Suzanne Eldridge: None declared, Aida Barawi: None declared, Hui Wang: None declared, Anke Roelofs: None declared, Magdalena Kaneva: None declared, Zeyu Guan: None declared, Helen Lydon: None declared, Bethan Thomas: None declared, Anne-Sophie Thorup: None declared, Beatriz F Fernandez: None declared, Sara Caxaria: None declared, Danielle Strachan: None declared, Ahmed Ali: None declared, Kanatheepan Shanmuganathan: None declared, Costantino Pitzalis: None declared, James Whiteford: None declared, Fran Henson: None declared, Andrew McCaskie: None declared, Cosimo De Bari: None declared, Francesco Dell’Accio Consultant of: F.D. has received consultancy fees from Samumed and UCB.

[Epidemiological characteristics of malaria in Henan Province from 1950 to 2019]

OBJECTIVE

To analyze the epidemiological characteristics of malaria in Henan Province from 1950 to 2019, so as to provide the scientific evidence for consolidating malaria elimination achievements in the province.

METHODS

The epidemiological situation of malaria and demographic data in Henan Province from 1950 to 2019 were collected, and the statistical analyses were performed using a descriptive epidemiological method. The spatial temporal distribution of malaria cases was identified using the software ArcGIS version 10.3.

RESULTS

During the period from 1950 through 2019, the progress of malaria elimination was divided into 4 stages in Henan Province, including the baseline-survey and key-control stage, morbidity-control and incidence-reduction stage, basic-eradication and achievement-consolidation stage and elimination stage. The spatial distribution of malaria cases shifted from south of the Huai River and the plain regions between the Yellow River and Taihang Mountain to the Huang-Huai-Hai Plain and Nanyang Basin, then was concentrated in eastern part of southern Huai River where Anopheles anthropophagus was distributed, and finally was gradually under control following malaria outbreak in Eastern Henan Plain. In addition, the species of Plasmodium changed from P. vivax, P. falciparum and P. malariae co-endemics to a single P. vivax infection, and the current co-endemics of 5 invasive malaria parasites, and the malaria vectors shifted from co-existence of Anopheles sinensis and An. anthropophagus to An. sinensis alone.

CONCLUSIONS

There has been a large change in the epidemiological characteristics of malaria in Henan Province from 1950 to 2019. Although malaria has been eliminated in Henan Province, the consolidation of the malaria elimination achievements remain a great challenge due to overseas imported malaria.

Robotic Assisted Transvaginal Notes Hysterectomy

Study Objective

To demonstrate a novel approach to transvaginal natural orifice transluminal endoscopic surgery (vNOTES) hysterectomy with bilateral salpingectomy using robotic assistance

Design

Video presentation of the surgical procedure.

Setting

University hospital.

Patients or Participants

A 34-year-old G2P1011 with one prior cesarean section and myomectomy complained of dysmenorrhea and chronic pelvic pain and requested for the most minimally invasive form of hysterectomy.

Interventions

A robotic-assisted transvaginal hysterectomy with bilateral salpingectomy was performed. The surgery began as a conventional transvaginal hysterectomy. An anterior and posterior colpotomy were performed, as which point, a camera was inserted to improve visibility. This allowed for confirmation of suspected adhesions from the patient's surgical history, most notably present in the anterior cul-de-sac between the bladder and uterus. Wristed instruments of the robot, the monopolar scissors and bipolar grasper, were also placed which enabled better navigation in the narrow surgical space. The remainder of the surgery, including the lysis of the dense adhesions, was completed smoothly with robotic assistance. The vaginal cuff was closed with a continuous running v-loc. The pelvis was inspected upon conclusion of the procedure and hemostasis was observed throughout.

Measurements and Main Results

The surgery was completed in 90 mins without complications. The patient was discharged on the same day. On follow-up, the patient noted that her post-operative pain was significantly less than what she had experienced after her previous myomectomy.

Conclusion

We showed that robotic-assisted NOTES is a novel and feasible option for transvaginal hysterectomy in indicated patients, particularly those with abnormal pathologies such as dense adhesions. In addition to image-guidance, robotic surgery allows for full articulation of instruments required for this surgery, which improves ease and access over other methods like laparoscopic surgery.

The importance of proper and prompt treatment of ocular syphilis: a lesson from permanent vision loss in 52 eyes

BACKGROUND

Ocular involvement can occur at any stage of syphilis. Prompt diagnosis and proper treatment of ocular syphilis are vital to avoid long-term consequences.

OBJECTIVES

To describe the risk factors for ocular syphilis and clinical features of blindness caused by syphilis.

METHODS

We report risk factors for ocular syphilis amongst patients seen at the Shanghai Skin Disease Hospital between October 2009 and October 2017. We identify patients with ocular syphilis resulting in blindness and report the clinical characteristics, laboratory findings and treatment outcomes of these patients.

RESULTS

A total of 8310 new cases of syphilis were seen, of which 213 patients had ocular disease and 50 patients had blindness due to syphilis. Increasing age and higher RPR titres were associated with ocular involvement but there was no association with HIV status. Blindness in syphilis was restricted predominantly to patients with optic nerve involvement and not patients with isolated uveitis. Fifty patients (and a total of 67 eyes) met the WHO definition of blindness prior to treatment for syphilis. At the end of follow-up, vision had improved in 24 of 67 eyes (35.8%) after treatment. Successful treatment of uveitis was associated with the best improvement in visual acuity, whilst patient with underlying optic atrophy prior to treatment had the worst visual outcome.

CONCLUSIONS

Ocular involvement is an important manifestation of syphilis which may result in blindness. Our data demonstrate outcomes for ocular syphilis are poor if detected late; early recognition and diagnosis is therefore vital to avoid permanent visual loss.

Purinoceptors, renal microvascular function and hypertension

Proper renal blood flow (RBF) and glomerular filtration rate (GFR) are critical for maintaining normal blood pressure, kidney function and water and electrolyte homeostasis. The renal microvasculature expresses a multitude of receptors mediating vasodilation and vasoconstriction, which can influence glomerular blood flow and capillary pressure. Despite this, RBF and GFR remain quite stable when arterial pressure fluctuates because of the autoregulatory mechanism. ATP and adenosine participate in autoregulatory control of RBF and GFR via activation of two different purinoceptor families (P1 and P2). Purinoceptors are widely expressed in renal microvasculature and tubules. Emerging data show altered purinoceptor signaling in hypertension-associated kidney injury, diabetic nephropathy, sepsis, ischemia-reperfusion induced acute kidney injury and polycystic kidney disease. In this brief review, we highlight recent studies and new insights on purinoceptors regulating renal microvascular function and renal hemodynamics. We also address the mechanisms underlying renal microvascular injury and impaired renal autoregulation, focusing on purinoceptor signaling and hypertension-induced renal microvascular dysfunction. Interested readers are directed to several excellent and comprehensive reviews that recently covered the topics of renal autoregulation, and nucleotides in kidney function under physiological and pathophysiological conditions (Inscho 2009, Navar et al. 2008, Carlstrom et al. 2015, Vallon et al. 2020).

First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate

Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides.

Functional expression of the Spodoptera exigua chitinase to examine the virtually screened inhibitor candidates

Chitinase is responsible for insect chitin hydrolyzation, which is a key process in insect molting and pupation. However, little is known about the chitinase of Spodoptera exigua (SeChi). In this study, based on the SeChi gene (ADI24346) identified in our laboratory, we constructed the recombinant baculovirus P-Chi for the expression of recombinant SeChi (rSeChi) in Hi5 cells. The rSeChi was purified by chelate affinity chromatography, and the purified protein showed activity comparable with that of a commercial SgChi, suggesting that we harvested active SeChi for the first time. The purified protein was subsequently tested for enzymatic properties and revealed to exhibit its highest activity at pH 8 and 40 C. Using homology modeling and molecular docking techniques, the three-dimensional model of SeChi was constructed and screened for inhibitors. In two rounds of screening, twenty compounds were selected. With the purified rSeChi, we tested each of the twenty compounds for inhibitor activity against rSeChi, and seven compounds showed obvious activity. This study provided new information for the chitinase of beet armyworm and for chitinase inhibitor development.

Mir-138-5p acts as a tumor suppressor by targeting pyruvate dehydrogenase kinase 1 in human retinoblastoma

OBJECTIVE

MicroRNAs have caught more attention for their role in tumor progression. Retinoblastoma (RB) is one of these ordinary malignant tumors. This study aims to identify whether mir-138-5p can regulate the development of RB, and find out its potential mechanism.

MATERIALS AND METHODS

Mir-138-5p expression in RB cells was monitored by RT-qPCR. Besides, the role of mir-138-5p in RB development was explored through function experiments in vitro. The potential mechanism was further explored by RT-qPCR, luciferase assay, and Western blot assay.

RESULTS

In our investigation, mir-138-5p was lower-expressed in RB cells than that in retinal pigment epithelial cells. Moreover, overexpression of mir-138-5p repressed cell viability, migration and invasion, and induced apoptosis of RB cells, while downregulated mir-138-5p increased cell viability, migration and invasion, and reduced apoptosis of RB cells. Furthermore, pyruvate dehydrogenase kinase 1 (PDK1) could be downregulated via overexpression of mir-138-5p, while PDK1 was upregulated via knockdown of mir-138-5p.

CONCLUSIONS

Our results suggested that mir-138-5p could repress the development of RB via suppressing PDK1, which may offer a new vision for interpreting the mechanism of RB tumorigenesis.

ZB transposon and chicken vasa homologue (Cvh) promoter interact to increase transfection efficiency of primordial germ cells in vivo

1. In order to increase the efficiency of generating transgenic chicken, this trial focused on two points: primordial germ cells (PGCs）transfection in vivo and a germline-specific promoter.2. In order to transfect PGCs in vivo, two plasmids (pZB-CAG-GFP, pCMV-ZB）were co-injected into chicken embryos via the subgerminal cavity at Hamburger and Hamilton (HH) stage 2-3 or via blood vessel at HH stage 13-14. Results showed that the percentage of GFP+ embryos, viability and hatching rate of embryos injected at HH stage 13-14 were significantly higher than that at HH stage 2-3.3. Two plasmid transposon systems were used for chicken embryo micro-injections. The donor plasmid, with a green fluorescent protein (GFP) reporter gene, was mediated by the ZB transposon. The helper plasmid was a transposase expression vector driven by the promoter of the chicken vasa homologue (Cvh) gene or Human cytomegalovirus (CMV) promoter. Results showed that 60.98% of gonads in Cvh group expressed GFP, which was 52.50% higher than seen in the CMV group. Only gonad tissue from the Cvh group showed any GFP signal, whereas both gonads and other tissues in the CMV group showed green fluorescence.4. The data suggested that ZB transposon-mediated gene transfer was efficient for transfecting PGCs in vivo; the Cvh promoter drove the transposase gene specifically in the germline and increased the efficiency of germline transmission. Blood vessels injection at HH stage 13-14 may be a more efficient route for PGCs transfection in vivo.

Fluid-enhanced surface diffusion controls intraparticle phase transformations

Phase transformations driven by compositional change require mass flux across a phase boundary. In some anisotropic solids, however, the phase boundary moves along a non-conductive crystallographic direction. One such material is Li_XFePO₄, an electrode for lithium-ion batteries. With poor bulk ionic transport along the direction of phase separation, it is unclear how lithium migrates during phase transformations. Here, we show that lithium migrates along the solid/liquid interface without leaving the particle, whereby charge carriers do not cross the double layer. X-ray diffraction and microscopy experiments as well as ab initio molecular dynamics simulations show that organic solvent and water molecules promote this surface ion diffusion, effectively rendering Li_XFePO₄ a three-dimensional lithium-ion conductor. Phase-field simulations capture the effects of surface diffusion on phase transformation. Lowering surface diffusivity is crucial towards supressing phase separation. This work establishes fluid-enhanced surface diffusion as a key dial for tuning phase transformation in anisotropic solids.

[Retinal image quality in northern rural Chinese adult population]

Objective: To assess the retinal image quality of the normal northern rural Chinese adult population. Methods: A normal population-based, cross-sectional study. From Oct, 2012 to Jan 2013, a clustered, random sampling procedure was used to select normal population who visual acuity≤ 0(LogMAR) and 30-69 years old from 2 villages. All eligible subjects were invited to undergo a comprehensive eye examination, and the retinal image quality related index were examined with pupil 4 mm using objective optical quality analysis systemⅡ(OQAS Ⅱ, Visiometrics, Spain), including MTFcutoff, VA20, VA9, PSF50, PSF10, OSI, SR. And describe the retinal image quality of different age group, including 30-39y, 40-49y, 50-59y, 60-69y. Results: Among 1 108 participants (61.9%) that completed examinations in our center, 681 participants (1 362 eyes) were recruited. There were 146, 586, 440 and 190 eyes in each group. The spherical equivalent refraction of each group was (-0.35±0.84), (-0.19±0.50), (-0.03±0.54) and (0.20±0.71) D. The best corrected vision acuity of each group was -0.02±0.04, -0.01±0.03, -0.01±0.02 and -0.00±0.01. The MTFcutoff of each group was (37.06±9.31), (36.69±8.93), (36.52±9.05) and (32.61±10.08) c/deg. Retinal imaging parameters were significantly different(MTFcutoff: MD=4.45, SR:MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, A9:MD=0.09, OSI:MD=-0.41, P<0.001)between aged 30-39 group and aged 60-69 group. Objective scattering index (OSI) were significantly different(MD=-0.13, P=0.004)between aged 30-39 group and aged 50-59 group. Retinal imaging parameters were significantly different(MTFcutoff:MD=4.45, SR:MD=0.03, PSF50:MD=-0.45, PSF10:MD=-2.87, VA20:MD=0.13, VA9: MD=0.09, OSI: MD=-0.41, P<0.001)between aged 40-49 group and aged 60-69 group. Retinal imageing parameters were significantly different(MTFcutoff: MD=4.45, SR: MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, VA9:MD=0.09, OSI:MD=-0.41,P<0.001)between aged 50-59 group and aged 60-69 group. Conclusion: Retinal image quality was gradually worse over time in the northern rural Chinese adult population. (Chin J Ophthalmol, 2018, 54:593-598).

Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles

AIM

Sphingosine-1-phosphate (S1P) influences resistance vessel function and is implicated in renal pathological processes. Previous studies revealed that S1P evoked potent vasoconstriction of the pre-glomerular microvasculature, but the underlying mechanisms remain incompletely defined. We postulated that S1P-mediated pre-glomerular microvascular vasoconstriction involves activation of voltage-dependent L-type calcium channels (L-VDCC) and the rho/rho kinase pathway.

METHODS

Afferent arteriolar reactivity was assessed in vitro using the blood-perfused rat juxtamedullary nephron preparation, and diameter was measured during exposure to physiological and pharmacological agents.

RESULTS

Exogenous S1P (10^-9 -10^-5 mol L^-1 ) evoked concentration-dependent vasoconstriction of afferent arterioles. Superfusion with nifedipine, a L-VDCC blocker, increased arteriolar diameter by 39 ± 18% of baseline and significantly attenuated the S1P-induced vasoconstriction. Superfusion with the rho kinase inhibitor, Y-27632, increased diameter by 60 ± 12% of baseline and also significantly blunted vasoconstriction by S1P. Combined nifedipine and Y-27632 treatment significantly inhibited S1P-induced vasoconstriction over the entire concentration range tested. In contrast, depletion of intracellular Ca²⁺ stores with the Ca²⁺ -ATPase inhibitors, thapsigargin or cyclopiazonic acid, did not alter the S1P-mediated vasoconstrictor profile. Scavenging reactive oxygen species (ROS) or inhibition of nicotinamide adenine dinucleotide phosphate oxidase activity significantly attenuated S1P-mediated vasoconstriction.

CONCLUSION

Exogenous S1P elicits potent vasoconstriction of rat afferent arterioles. These data also demonstrate that S1P-mediated pre-glomerular vasoconstriction involves activation of L-VDCC, the rho/rho kinase pathway and ROS. Mobilization of Ca²⁺ from intracellular stores is not required for S1P-mediated vasoconstriction. These studies reveal a potential role for S1P in the modulation of renal microvascular tone.

Development of an Open Metadata Schema for Prospective Clinical Research (openPCR) in China

Objectives: In China, deployment of electronic data capture (EDC) and clinical data management system (CDMS) for clinical research (CR) is in its very early stage, and about 90% of clinical studies collected and submitted clinical data manually. This work aims to build an open metadata schema for Prospective Clinical Research (openPCR) in China based on openEHR archetypes, in order to help Chinese researchers easily create specific data entry templates for registration, study design and clinical data collection.

Methods: Singapore Framework for Dublin Core Application Profiles (DCAP) is used to develop openPCR and four steps such as defining the core functional requirements and deducing the core metadata items, developing archetype models, defining metadata terms and creating archetype records, and finally developing implementation syntax are followed.

Results: The core functional requirements are divided into three categories: requirements for research registration, requirements for trial design, and requirements for case report form (CRF). 74 metadata items are identified and their Chinese authority names are created. The minimum metadata set of openPCR includes 3 documents, 6 sections, 26 top level data groups, 32 lower data groups and 74 data elements. The top level container in openPCR is composed of public document, internal document and clinical document archetypes. A hierarchical structure of openPCR is established according to Data Structure of Electronic Health Record Architecture and Data Stand -ard of China (Chinese EHR Standard). Meta-data attributes are grouped into six parts: identification, definition, representation, relation, usage guides, and administration.

Discussions and Conclusion: OpenPCR is an open metadata schema based on research registration standards, standards of the Clinical Data Interchange Standards Consortium (CDISC) and Chinese healthcare related stand -ards, and is to be publicly available throughout China. It considers future integration of EHR and CR by adopting data structure and data terms in Chinese EHR Standard. Archetypes in openPCR are modularity models and can be separated, recombined, and reused. The authors recommend that the method to develop openPCR can be referenced by other countries when designing metadata schema of clinical research. In the next steps, openPCR should be used in a number of CR projects to test its applicability and to continuously improve its coverage. Besides, metadata schema for research protocol can be developed to structurize and standardize protocol, and syntactical interoperability of openPCR with other related standards can be considered.

High n-type and p-type thermoelectric performance of two-dimensional SiTe at high temperature

2D β-SiTe is predicted to be a promising high-temperature thermoelectric material with a balanced n- and p-type performance.

A rating scale for the severity of Guillain-Barré syndrome

INTRODUCTION

The objective of this study was to develop a rating scale to assess the severity of Guillain-Barré syndrome (GBS).

METHODS

The preliminary rating scale, which contained 11 items, was developed by the Delphi method, and data of 258 patients were collected to evaluate it. Item analysis was accomplished by 100 patients; the additional 158 patients were used to evaluate the reliability, validity, and discriminative ability of the rating scale. The structure of the rating scale was testified by the confirmatory factor analysis and also made a further evaluation by the correlation analysis.

RESULTS

The rating scale contained 10 items. The three factors mainly generalized the motor function, cranial nerve function and autonomic function. The results of reliability and validity showed that the structure of the rating scale was good (χ² =68.25, df=32, χ² /df=2.13, normed fit index (NFI)=0.919, non-normed fit index (NNFI)=0.936, comparative fit index (CFI)=0.96, a root mean square error of approximation (RMSEA)=0.085), and the Cronbach's α coefficient for the scale was .852, with the three dimensions ranging from .585 to .752.

CONCLUSION

Reliability and validity of the rating scale are all satisfied. The scale contained the main clinical presentations of GBS, and it is suitable to evaluate the severity of GBS.