Association between ambient particulate matter exposure and semen quality in fertile men

Background Several studies have suggested adverse effects of particulate matter (PM) exposure on male reproductive health; few have investigated the association between PM exposure and semen quality in a large population of fertile men. Methods We evaluated 14 parameters of semen quality in 1554 fertile men in Nanjing from 2014 to 2016. Individual exposure to particular matter ≤10 μm in diameter (PM10) and ≤ 2.5 μm in diameter (PM2.5) during key periods of sperm development (0-90, 0-9, 10-14, 15-69, and 70-90 days before semen collection) were estimated by inverse distance weighting interpolation. Associations between PM exposure and semen quality were estimated using multivariable linear regression. Results Higher 90-days average PM2.5 was in association with decreased sperm motility (2.21% for total motility, 1.93% for progressive motility per 10 μg/m3 increase, P < 0.001) and four quantitative aspects of sperm motion (curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), and amplitude of lateral head displacement (ALH), P < 0.01). The association between PM2.5 exposure and semen quality were generally stronger for the earlier exposure window (70-90 days prior to ejaculation) than for recent exposure (0-9, 10-14, or 15-69 days). In the subgroup of men who had normal sperm parameters (n = 1019), similar results were obtained. Ninety-days PM10 exposure was associated only with decreased VCL and VAP and was not related to sperm concentration. Conclusions Exposure to PM2.5 adversely affects semen quality, specifically lower sperm motility, in fertile men. Graphical abstract

Solving string constraints with Regex-dependent functions through transducers with priorities and variables

Regular expressions are a classical concept in formal language theory. Regular expressions in programming languages (RegEx) such as JavaScript, feature non-standard semantics of operators (e.g. greedy/lazy Kleene star), as well as additional features such as capturing groups and references. While symbolic execution of programs containing RegExes appeals to string solvers natively supporting important features of RegEx, such a string solver is hitherto missing. In this paper, we propose the first string theory and string solver that natively provides such support. The key idea of our string solver is to introduce a new automata model, called prioritized streaming string transducers (PSST), to formalize the semantics of RegEx-dependent string functions. PSSTs combine priorities, which have previously been introduced in prioritized finite-state automata to capture greedy/lazy semantics, with string variables as in streaming string transducers to model capturing groups. We validate the consistency of the formal semantics with the actual JavaScript semantics by extensive experiments. Furthermore, to solve the string constraints, we show that PSSTs enjoy nice closure and algorithmic properties, in particular, the regularity-preserving property (i.e., pre-images of regular constraints under PSSTs are regular), and introduce a sound sequent calculus that exploits these properties and performs propagation of regular constraints by means of taking post-images or pre-images. Although the satisfiability of the string constraint language is generally undecidable, we show that our approach is complete for the so-called straight-line fragment. We evaluate the performance of our string solver on over 195000 string constraints generated from an open-source RegEx library. The experimental results show the efficacy of our approach, drastically improving the existing methods (via symbolic execution) in both precision and efficiency.

A System for Accurate Deployment of Unconstrained Triple-Fenestrated Aortic Arch Endografts

Purpose: To achieve accurate rotational orientation and the axial position of unconstrained triple-fenestrated physician-modified endografts upon deployment in the aortic arch during total arch thoracic endovascular aortic repair (TA-TEVAR). Materials and Methods: Following a detailed study of reconstructed computerized tomography angiography images of patients’ arch anatomy, customized, sealable fenestrations with radio-opaque margins are created onsite on Valiant Captivia (Medtronic) endografts, transposing the arch branch ostial anatomic interrelationship onto the endograft precisely. Radio-opaque figure-of-8 markers, indicating the 12 o’clock (superior) position, are attached to the endograft on the surface and brought up to the surface under the endograft cover during resheathing. Resheathing without any twist in the endograft is achieved by lining up the welds in each endograft stent segment in a straight line. The fluoroscopic working view for arch endograft delivery and deployment is the left anterior oblique view that is orthogonal to the plane of the arch, which, in turn, is the right anterior oblique view in which parts of a stiff indwelling guidewire in the ascending and descending aorta precisely overlap. During introduction in the working view, the endograft delivery system is rotated in the descending thoracic aorta so that the 12 o’clock figure-of-8 markers are viewed on the edge and situated at the outer aortic curvature; continued advancement into the arch without any further rotation will ensure superior orientation of the figure-of-8 markers and, consequently, correct endograft rotational orientation. Proper axial endograft positioning requires locating the left common carotid artery (LCCA) fenestration just proximal to a taut externalized LCCA-femoral guidewire loop marking the posterior limit of the LCCA ostium. After endograft deployment during rapid cardiac pacing, the target arch branches are cannulated through their respective fenestrations using hydrophilic 0.035-inch guidewires that are externalized via distal sheaths to create femoral-arch branch (through-and-through) loops over which covered fenestrated stents are introduced and deployed. Results: This technique was used successfully in 31 consecutive patients undergoing TA-TEVAR; systemic blood pressure was obtained in all arch branches immediately after endograft deployment, indicating adequate blood flow. All arch branches were successfully cannulated and stented. Conclusion: This system enables accurate deployment of unconstrained triple-fenestrated arch endografts simply and reliably during TA-TEVAR.

TELMISARTAN AND AZELNIDIPINE QUANTIFICATION EMPLOYING HPLC STRATAGEM; STABILITY INVESTIGATION ON TELMISARTAN AND AZELNIDIPINE

Objective: The focus of our research was to create a fairly sensitive HPLC stratagem for determining telmisartan (TLM) and azelnidipine (AEL) in bulk and tablet types. Methods: Analysis of TLM and AEL was performed on a “C18 Kromasil stationary column (5 µm, 250 mm × 4.6 mm)”. The mobile phase was made of 0.1M NaH2PO4 solution (pH 3.5) and methanol at a comparative volume ratio of 50% each. The analysis of TLM and AEL was isocratic, with the flow velocity adjusted at 1.0 ml/min and indeed, the TLM and AEL analysis was done at 256 nm using a PDA device sensor. TLM and AEL were stressed with acid, peroxide, dry heat, alkali, and sunlight-induced settings. Results: The retention/elution periods for the TLM and AEL were observed at 2.225 min and 3.178 min, respectively. The HPLC stratagem developed have a straight-line relation with relative concentrations in the ranges of 20-60 µg/ml for TLM and 4-12 µg/ml for AEL. The LOQ’s for TLM and AEL were 0.2516 μg/ml and 0.0871 μg/ml, respectively. The validation investigational findings done for TLM and AEL with the established sensitive HPLC stratagem were passed out in conformity with the ICH standards. Conclusion: The established sensitive HPLC stratagem was shown as competent for the quality check of bulk samples of TLM and AEL throughout batch release as well as in the course of TLM and AEL stability investigations.

Travel Reduction Control of Distributed Drive Electric Agricultural Vehicles Based on Multi-Information Fusion

In agricultural vehicles with internal combustion engines, owing to the use of rear-wheel drive or four-wheel drive, it is difficult to obtain information regarding the slip of the driving wheels. Excessive wheel slip, an inevitable phenomenon occurring during agricultural activities, can easily damage the original soil surface and result in excessive energy consumption. To solve these problems, a distributed drive agricultural vehicle (DDAV) based on multi-information fusion was proposed. The actual travel reduction of each wheel was calculated by determining the vehicle parameters in order to deliver the required torque to the four drive wheels via sliding mode control (SMC) and incremental proportional-integral (PI) control. Through this process, the vehicle always operates in a straight line. Test results show that, on a uniform surface, the travel reduction of each wheel can be maintained at the target value by using the incremental PI control strategy, with only minor fluctuations, to make the vehicle run in a straight line (R2 = 0.9999). Furthermore, on a separated surface, the travel reduction of each wheel can be maintained at the target value, and using the SMC strategy enables more identical coefficient of gross tractions for each wheel to make the vehicle run in a straight line (R2 = 0.9902). Unlike the non-control strategy, the vehicle reaches a stable state within 1 s, owing to the use of a controller that can effectively reduce the impact of road changes on vehicle velocity. This study can provide a reference for the drive control of DDAVs.

Characterization of the Propagation Route of Light Passing Through Convex Lens

Existing optical theory states that the light directed to the optical center of the convex lens will travel in a straight line. Does the theory hold? If this is true, then why the images formed by the camera lens tends to be distorted? To answer the question, this paper studied the propagation mode of light passing through convex lens. Specifically, assuming the propagation medium on both sides of convex lens is homogeneous, we propose an angular affine transformation (AAT) theory. Based on the proposed theory, we first derive the refractive index of convex lens as well as the method of calculating the normal direction of each point within the radius of convex lens radius and then derive the refraction direction of each point within the radius of convex lens, thus completely characterizing the path diagram of light directed to the optical center. The correctness of the proposed theory has been verified using two sets of experiments: characterization of the route of light passing through the convex lens as well as camera imaging experiment. From the results, it can be concluded that the light directed to the optical center of convex lens does not travel in a straight line, but in a refraction line.

Interpreting the slope of a straight line in kinematics graphs with school students

The interdisciplinary nature of knowledge is one of the objectives promoted in Colombia, fostering in students the ability to recognize that the curriculum does not work in isolation; if knowledge is complementary, its joint development leads to better academic performance. This research is oriented towards showing an application of the mathematical concept of the slope of the straight line in physics applications, favoring the understanding of the relationships between variables, as occurs with the graphs of kinematics. A group of eleventh grade students from a private educational institution filled in a questionnaire for data collection, based on three situations proposed to answer three open questions in which a reasonably justified answer was required. A part of the group correctly interpreted the graphs by describing the characteristics of the movement in each time interval, but only a few were able to associate the slope of the line as the velocity or acceleration as a function of the variables mentioned in the graph, although their argumentation was based on the angle of elevation of the line.

Extraction of Zn (II) ions in an polypropylene glycol 425 - sodium chloride - water aqueous two-phase system

Liquid-liquid extraction is one of the most used separation methods in chemical technology for recovery and separation of metal ions, other inorganic and organic substances. It is known that for extraction of Zn(II) the most frequently used extractants are D2EHPA, Aliquat 336, etc., diluted in an organic solvent. The use of these reagents does not meet the principles of “green” chemistry. Thus, in the present work, the extraction system based on polypropylene glycol 425 and sodium chloride for the extraction of Zn(II) ions from aqueous solutions is proposed. Equilibrium values of the distribution coefficient in the proposed aqueous two-phase system have been determined. Dependence of metal distribution coefficient on time of phase contact is obtained, time to reach equilibrium was 10 minutes. The isotherm of Zn(II) extraction obtained in the proposed system is a straight line, which indicates the independence of the distribution coefficient from the initial concentration of metal in the solution. The received experimental data can be used at the creation of “green” schemes of processing of Ni-MH batteries.

Meaning of the derivative as a rate of change through a graphic argumentation. A case with Chilean students

From the socio-epistemology perspective, the teaching of the derivative is problematized due to the lack of reference frameworks that give variational meanings to the derivative and allow its construction by means of graphical arguments. The objective of this research was to analyze the construction of meanings of the derivative, as a rate of change, that Chilean students developed through a graphic argumentation in a specific situation of variation. In order to respond to the stated objective, a qualitative methodology was used, consisting of a case study, where a situation of variation was designed with the purpose of promoting the analysis of temperature changes in specific everyday life phenomena. This design was applied to ten Chilean high school students interested in studying engineering. As a result of the research, it was obtained that the participants, through a graphic argumentation, understood the slope of a straight line as a rate of change of temperature regarding time. It was concluded that this research provides elements for the construction of frames of reference that signify the derivative, as a rate of change, in situations of variation, valuing the graphic arguments and functional justifications that emerged from the students.