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Background Tumor-infiltrating lymphocytes (TILs) are major participants in the tumor microenvironment. The prognostic value of TILs in patients with pancreatic cancer is still controversial. Methods The aim of our meta-analysis was to determine the impact of FoxP3+Treg cells on the survival of pancreatic cancer patients. We searched for related studies in PubMed, EMBASE, Ovid, and Cochrane Library from the time the databases were established to Mar 30, 2017. We identified studies reporting the prognostic value of FoxP3+Treg cells in patients with pancreatic cancer. Overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS)/relapse-free survival (RFS) were investigated by pooling the data. The pooled hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the association between FoxP3+Treg cells and survival outcomes of pancreatic cancer patients. A total of 972 pancreatic cancer patients from 8 studies were included in our meta-analysis. Results High levels of infiltration with FoxP3+Treg cells were significantly associated with poor OS (HR=2.13; 95% CI 1.64–2.77; PP< 0.05). Similar results were also observed in the peritumoral tissue; high levels of FoxP3+Treg cells were associated with poor OS (HR =2.1795% CI, CI 1.50–3.13). Conclusion This meta-analysis indicated that high levels of intratumoral or peritumoral FoxP3+Treg cell infiltration could be recognized as a negative factor in the prognosis of pancreatic cancer.

We report successful growth of millimeter-sized high quality single crystals of V$_3$S$_4$, a candidate topological semimetal belonging to a low-symmetry space group and consisting of only low atomic number elements. Using density functional theory calculations and angle-resolved photoemission spectroscopy, we show that the nonmagnetic phase of monoclinic V$_3$S$_4$ hosts type-II Dirac-like quasiparticles which opens a sizable gap due to spin orbit coupling, as well as theoretical multiple nodal lines that are eliminated also by spin orbit coupling. These results suggest that relativistic effects give rise to profound modifications of the topological properties even in compounds with low-weight elements., 19 Pages, 3 Figures. To be published in Journal of Alloys and Compounds

BACKGROUND Spontaneous bladder rupture is relatively rare, and common causes of spontaneous bladder rupture include bladder diverticulum, neurogenic bladder dysfunction, gonorrhea infection, pelvic radiotherapy, etc. Urinary bladder perforation caused by urinary catheterization mostly occurs during the intubation process. CASE SUMMARY Here, we describe an 83-year-old male who was admitted with 26 h of middle and upper abdominal pain and a history of long-term catheterization. Physical examination and computed tomography of the abdomen supported the diagnosis of diffuse peritonitis, most likely from a perforated digestive tract organ. Laparoscopic exploration revealed a possible digestive tract perforation. Finally, a perforation of approximately 5 mm in diameter was found in the bladder wall during laparotomy. After reviewing the patient’s previous medical records, we found that 1 year prior the patient underwent an ultrasound examination showing that the end of the catheter was embedded into the mucosal layer of the bladder. Therefore, the bladder perforation in this patient may have been caused by the chronic compression of the urinary catheter against the bladder wall. CONCLUSION For patients with long-term indwelling catheters, there is a possibility of bladder perforation, which needs to be dealt with quickly.

Background Duplication of the appendix is an infrequent congenital malformation with a complex classification. The horseshoe appendix is a subtype of the duplex appendix and is rarely reported in the literature. Endometriosis is a common gynecological disease that rarely occurs in the appendix. Moreover, horseshoe appendix combined with endometriosis has not been previously reported. Case summary Here, we describe a 44-year-old woman who was admitted with a 1-d history of migratory lower right quadrant pain. Physical examination was consistent with the signs of acute appendicitis. The patient underwent an emergency exploratory laparotomy. The distal tip of the appendix was in contact with the cecum by another base, or "horseshoe appendix". In addition, a small intestinal mass and an ovarian mass were identified. Subsequently, appendectomy, partial resection of the small intestine, and right oophorectomy were successively performed. The histopathology confirmed the diagnosis of acute inflammation of the duplex appendix with endometriosis, small intestine endometriosis, and ovarian endometriosis. Conclusion Surgeons need to be aware of the possibility of the duplex appendix when performing an appendectomy, and this study emphasizes the importance of exploring the entire abdomen.

Today East Asia harbors many “relict” plant species whose ranges were much larger during the Paleogene-Neogene and earlier. The ecological and climatic conditions suitable for these relict species have not been identified. Here, we map the abundance and distribution patterns of relict species, showing high abundance in the humid subtropical/warm-temperate forest regions. We further use Ecological Niche Modeling to show that these patterns align with maps of climate refugia, and we predict species’ chances of persistence given the future climatic changes expected for East Asia. By 2070, potentially suitable areas with high richness of relict species will decrease, although the areas as a whole will probably expand. We identify areas in southwestern China and northern Vietnam as long-term climatically stable refugia likely to preserve ancient lineages, highlighting areas that could be prioritized for conservation of such species., We acknowledge funding by the Global Environmental Research (S-14) of the Ministry of the Environment (Japan), the Proyecto Intramural Especial, PIE (grant no. 201630I024) from the CSIC, Spain, the Natural Science Foundation Project of CQ CSTC (cstc2016jcyjA0379) (China), and the Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University (Thailand).

Zinc-oxygen batteries are promising candidates for electrical vehicles and electric grid energy storage due to their low cost, high safety levels, and low environmental impact. The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) represent the most significant processes in zinc-oxygen batteries. The development of nonprecious metal catalysts for OER with satisfactory performances and low cost (especially prepared by a straightforward synthesis route), still poses a significant challenge. Herein, we report an exceptionally facile and easily scalable method to produce NiFe layered double hydroxide (LDH) coated nickel foam by immersing nickel foams into aqueous solutions containing NiCl2 and FeCl2 and keeping them standing for a certain period of time. Without any other complicated technique or organic reagent, microflower-shaped NiFe LDHs can be obtained. The resulting electrode shows excellent OER performance with a low overpotential of 210 mV at a 10 mAcm(-2) constant current polarization and stable operation for more than 100 charge-discharge cycles in zincoxygen batteries.

In the original version of this Article, an incorrect sample size was provided for the number of relict species (443 instead of 442) and the number of relict forests (423 instead of 422). These errors have been corrected in both the PDF and HTML versions of the Article.

MnO2 nanostructures were successfully synthesized by a magnetic-field-assisted hydrothermal approach. By applying a pulsed magnetic field to the reaction system, the crystal phase transformation progress of MnO2 at different temperature has been changed comparing to those synthesized without magnetic field. The effect of pulsed magnetic field on the growth of MnO2 was investigated by tracking the phase of the sample by using X-ray diffraction. It is found the pulsed magnetic field has an obvious effect on the nucleation and growth of MnO2 nanostructures and therefore influences the phase transformation.

We report the preparation of quasi-arrays of aluminum nitride nanocones via chemical vapor deposition on nitriding treated titanium substrate at 800 °C through the reaction between AlCl3 vapor and NH3/N2 gas. The field emission measurement exhibits a fine electron emission with the turn-on field of 10.7 V/mm, which is quite smaller than the turn-on field of 41.3 V/μm for aluminum nitride nanocones deposited on silicon wafer in our previous works. The reduction of turn-on field is attributed to the formation of a layer of conductive tiannium nitride on titanium substrate during the nitriding treatment.

Pulsed magnetic field was first employed in the study on MgB2 superconductors. Superconductivity properties and microstructures of Zn and SiC doped MgB2 were discussed in this paper. The superconductors showed different superconductivities after magnetic sintering. Critical current density and flux pinning force were relevant to the dopants properties in MgB2. Grains in the pulsed magnetic processed MgB2 matrix were smaller than those in the normal processed one. The refinement microstructures have caused the critical current density (Jc) anisotropy in both the Zn and SiC doped MgB2.

Automated aircraft control has traditionally been divided into distinct functions that are implemented separately (e.g., autopilot, auto-throttle, flight management); each function has its own fault-tolerant computer system, and dependencies among different functions are generally limited to the exchange of sensor and control data. A by-product of this federated architecture is that faults are strongly contained within the computer system of the function where they occur and cannot readily propagate to affect the operation of other functions.More modern avionics architectures contemplate supporting multiple functions on a single, shared, fanlt-tolerant computer system where natural fault containment boundaries are less sharply defined. Partitioning uses appropriate hardware and software mechanisms to restore strong fault containment to such integrated architectures.This paper examines the formal specification of partitioning and the mathematical properties in providing assurance for partitioning.

This paper proposes a new approach to resolve the problem of device driver development: To design a domain specific language, named DEVIL+ . With this language, users can write a complete device driver, including: interrupt handler, timer controller, logic controller and so on. DEVIL+ allows a description to be checked for consistency and completeness. This not only improves the safety of the device driver but also uncovers bugs as early as possible in the development process.

In this paper we present a formal semantic definition of a device interface language called DEVIL (DEVice Interface Language). The semantic model is based on a high-order logic system supported by a mathematical theorem proof development system called PowerEpsilon . This work is intended for fully understanding semantics of DEVIL and will be used as a reference-guide in implementation project for the embedded real-time operating system δ- OS .

Habitat heterogeneity plays a key role in the dynamics and structures of communities. In this article, a two-species metapopulation model that includes local competitive dynamics is analyzed to study the population dynamics of two competing species in spatially structured habitats. When local stochastic extinction can be ignored, there are, as in Lotka-Volterra equations, four outcomes of interspecific competition in this model. The outcomes of competition depend on the competitive intensity between the competing pairs. An inferior competitor and a superior competitor, or two strongly competing species, can never stably coexist, whereas two weak competitors (even if they are very similar species) may coexist over the long term in such environments. Local stochastic extinction may greatly affect the outcomes of interspecific competition. Two competing species can or cannot stably coexist depending not only on the competitive intensity between the competing pairs but also on their precompetitive distributions. Two weak competitors that have similar precompetitive distributions can always regionally coexist. Two strongly competing species that competitively exclude each other in more stable habitats may be able to stably coexist in highly heterogenous environments if they have similar precompetitive distributions. There is also a chance for an inferior competitor to coexist regionally or even to exclude a superior competitor when the superior competitor has a narrow precompetitive distribution and the inferior competitor has a wide precompetitive distribution.

Programming in constructive type theory corresponds to theorem proving in mathematics: the specification plays the role of the proposition to be proved and the program is obtained from the proof. In this paper, we present an approach of using constructive type theory to derive a compiler of a given programming language from its denotational semantic definition. The development is supported by a proof development system called PowerEpsilon .

Programming in constructive type theory corresponds to theorem proving in mathematics: the specification plays the role of the proposition to be proved and the program is obtained from the proof. In this paper, we present an approach of using constructive type theory to derive a debugger of a given programming language from its denotational semantic definition. The development is supported by a proof development system called PowerEpsilon .

Embedded and real-time applications are appearing in a wider variety and in more critical applications than ever before, and they are generating more revenue from the services they provide. At the same time, these applications are growing larger and more complex as the market calls for higher performance and reduced costs. To meet market demands and reduce the risks inherent in building complex systems, manufacturers must find and apply technologies that help reach their goals and minimize risks without having to reinvent the wheel.While these issues are common to every high-tech industry, they are particularly significant in embedded real-time applications where failures can cause enormous losses in revenue or even loss of life (for example, in process-control situations). Increasing performance, reducing costs and lowering risks continue to be the prime objective in the embedded systems marketplace. The RTOS reliability factor becomes more critical as companies build upon and expand existing infrastructures, and as it becomes increasingly common for applications of all types to interact with each other. The reliability of your RTOS may not only affect the success of your product, but it can also impact the effectiveness of a host of related products. Indeed, it only takes one OS failure before your customer moves on to your competitor.How to make sure that an operating system is correct and reliable? There are perhaps three ways or there are three categories.• The Market Proven Operating Systems: Those operating systems have been in market for over 10-15 years and have been used in many safety-critical applications. They are therefore tested by the customers for a long time and many errors have been found and corrected. This kind of operating systems include pSOSystem, VxWorks and VRTX. However, this does not mean that these operating systems are safe and reliable. Some market proven operating systems are not correct and reliable. For instance, Microsoft Windows and Windows NT. Therefore, market proving does not prove anything.• The Certificated Operating Systems: Those operating systems have been validated by some internationally recognized organizations through a very systematic testing approach. This kind of operating system includes OSE and Ada. The certification is achieved by systematically passing several thousand test cases to the system to see if the system is still running correctly. Testing can only help you to find out that your program has a bug. It cannot tell you that your program has no bugs.• The Provably Correct Operating Systems: The operating systems were developed starting from a formally defined semantic specification and were derived through a rigorous method. Some important properties such as the safety, correctness, deterministics, reliability and high-availability have been proved during the development.δ- Core developed by CoreTech is perhaps the first commercial operating system which has been proven to be correct against a formal specification. The whole proof is conducted using a in-house developed mathematical proof development system - PowerEpsilon.

This study is on the injection molding process for the fabricating anisotropic Nd-Fe-B bonded magnets. The effects of powder loading, particle size of the magnetic powder, polymer binder and the fabricating process on the magnetic and the mechanical properties of anisotropic Nd-Fe-B magnets were investigated. The proper powder loading, particle size and binder are 60%(vol%), 75–106 μm and PA 1010, respectively. The optimum condition for good magnetic properties of anisotropic injection bonded Nd-Fe-B magnets is mixing the binder and the chemicals in the temperature between 205–215 °C, injection temperature of 265 °C, the injection pressure of 5–6 MPa, the press time of 5 second, and molding temperature of 80 °C. The magnetic properties of anisotropic bonded Nd-Fe-B magnets made in above conditions from d-HDDR powder were: B r =0.72 T, i H c =983 kA/m, ( BH ) max =75 kJ/m c .

This work studied the application of the different magnetic field used in the compaction process for die fabrication of anisotropic Nd-Fe-B bonded magnet. The static field made from Nd-Fe-B permanent magnets was used in the blending process to separate the particles each other. The SEM observation gave intuitionistic results about it. The anisotropic Nd-Fe-B bonded magnets were fabricated with warm-compaction under the electromagnetic field about 2.5 T. It is known that magnetic field is necessary for anisotropic materials fabrication for alignment. And warm compaction was used to decrease the viscousness of binder, to enhance alignment magnetic particle while press, and to get high density materials. For coercivity of Nd-Fe-B magnets decrease largely with the temperature increasing, press in proper temperature and oriented field is benefit to the magnetic characteristics and the mechanical properties of the anisotropic bonded Nd-Fe-B magnets. Finally solidifying process was performed under the pulse field of 4 T. The increment for solidifying in the field was about 15% for maximum energy product of the bonded magnet. The magnetic properties of anisotropic bonded Nd-Fe-B magnets from d-HDDR powders compact at 90 °C in alignment field of 2.5 T were: B r =8.55 kGs, i H c =12.0 kOe, ( BH ) max =14.57 MGOe.

Transformational programming is a method for program development. To formalize the transformational programming techniques, the key point is to formally represent transformation rules and to prove the correctness of these rules. In this paper, we describe a constructive type-theoretical approach for formalizing the concepts of program schema, transformation rules and strategies, and software development processes. Some examples for verification and derivation of semantically correct program transformation rules are presented.

PowerEpsilon ([ZhuW9l]) is a strongly-typed polymorphic functional programming language based on Martin-Löf's type theory and the Calculus of Constructions. In PowerEpsilon there are no constant time definitions of the predecessor functions which will lead to non-efficient programs. In this paper, we give a solution to this problem by introducing an algebraic rewriting mechanism into the system.

Reflective programming languages were introduced in order to study programs that need knowledge of their own behavior. In artificial intelligence, this kind of knowledge is heeded, for example, in programs that must explain their behavior to a user. In the study of programming languages, a similar phenomenon occurs in extensible languages, that is, languages in which one can write programs that change the language itself. In this paper, we present an investigation of computational reflection mechanism in a higher-order λ-calculus - PowerEpsilon. We will show that PowerEpsilon is an extremely rich and powerful language for reflective computation.

To understand the dietary nutrients among rural stranded children.2551 children aged 2 to 7, including 1278 stranded children in the rural areas and another 127 children served as controls were selected, using multistage stratified cluster random sampling. Dietary survey was performed with three-day weighing dietary method and questionnaire on food intake. Data on diet were analyzed and evaluated by the Dietary Reference Intakes (DRIs) recommend by Chinese Nutrition Society, to evaluate the levels on energy and nutrient intake among stranded children in the rural areas.The dietary pattern among rural stranded children mainly consisted of grains and vegetables, but the intakes of animal products, fruits, and snacks were significantly less than in the control group. The intakes of three major energy-producing nutrients were below the recommend nutrient intake. Minerals as calcium, zinc, selenium, kalium and vitamins as vitamin A, B1, B2 were insufficient. Most of the rural stranded children took nutrients insufficiently, with 50% lack of adequate energy and 80% of protein, 90% of minerals (calcium, zinc etc.) and vitamins (vitamin BI and vitamin B2 etc.). Sources from high quality protein was insufficient, only consisting 35% of the total protein, but overabundant (over 64%) from the plants. The intake of plant-sources iron was overabundant, accounted for 87%.The dietary pattern was unsatisfactory with insufficient intake of energy-sources proteins and some nutrients. The sources of energy, protein, and iron were mostly obtained from underbalanced foods. It is necessary to improve the dietary nutrients status among rural stranded children aged 2-7 years.

To understand the status on care and nutrition of children living in the rural areas (so called 'left-behind' children) while their parents were seeking for jobs in the urban areas.Cross-sectional study was employed in this investigation. The group of 'left-behind' children (n = 774) and the comparison group (n = 774) were identified. The ascertainment methods mainly included questionnaire, anthropometrics measurements, food-frequency, and laboratory examination.Data from this study revealed that the guardians of the 'left-behind' children had less ability to ensure daily food that the children demanded than the control group and the 'left-behind' children were more likely to be poorly attended (chi2 = 6.671, P = 0.036; xhi2 = 15.053, P = 0.001). Mothers who chose to work outside of their households would tend to choose bottle-feeding or decrease the duration of breastfeeding for their infants (chi2 = 5. 051, P = 0.031; t = -7.201, P = 0.001). The intake of milk and bean products in children younger than 2 years old and cereal intake in children aged 2 to 4 in the group of 'left-behind' children were obviously lower than that seen in the control group (t = -2.150, P = 0.032; t = -2.054, P = 0.040 respectively). The 'left-behind' children were in high prevalence of anemia, and showed significant difference when comparing with the control group (chi2 = 4.560, P = 0.033).Children under 'left-behind' situation were in poor nutrition. Recognition of this situation by the communities, parents and extended families would facilitate more attention and effective intervention programs to improve the situation.

PowerEpsilon is a proof development system based on Martin-Lof's type theory and the calculus of constructions. It contains a logic, a specification language and a programming language, so it is a powerful tool with different uses, However, the constructive type theory is an integrated logic in which the logical and computational parts are associated so well that to extract a program from a proof is not a straightforward task. In this paper, a new approach for extracting program from a proof called type erasing is proposed. >

Programming in constructive type theory corresponds to theorem proving in mathematics: the specification plays the role of the proposition to be proved and the program is obtained from the proof. We present a proof development system called PowerEpsilon, based on a constructive type theory which can be used as a formal program development system for actually deriving a program from a specification. The synthesis of a unification algorithm is presented to show the power of the system.