Spontaneous Evolution Research Articles

Traitements par radiothérapie stéréotaxique : indications et situations cliniques particulières: Stereotactic radiotherapy: Indications and specific clinical settings

Lobectomy with radical lymph node dissection remains the gold standard treatment for stage I primary non-small cell lung cancer (NSCLC) but in recent years, stereotaxic radiotherapy (SBRT) have gradually taken their place in this indication. The choice of doses and fractionation and the stereotactic radiotherapy technique should be considered taking into account the patient’s clinical situation and the tumour to be treated (size and topography.)Some specials clinical setting as the treatment of ground glass opacity remain questionable without a lot of evidence in scientifics publications but offer a real alternative of treatment for inoperables patients. In regards to catch-up treatments, reirradiations offer new perspectives in case of local failure after stereotactic radiotherapy with promising results. But the majority of relapses are regional or metastatic and systemic treatment especially adjuvant immunotherapy is a very interesting treatment option for this frail patients, not enough fit to receive chemotherapy.The spontaneous evolution of NSCLC lung tumors without treatment remain very negative; The use of local non-surgical treatments as SBRT is an major option for the care of elderly patients who are not eligible for surgery. Despite their comorbidities, frailty and their poor remaining survival the majority of this patients will die of their lung cancer.© 2021 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Effectiveness of osteopathic care in the treatment of infant positional posterior plagiocephaly

Introduction.Posterior Positional plagiocephaly (PPP) is a cranial deformation seen in infants. The case number increased since 1992, following the supine sleeping advice. Most of the time several factors are combining together, leading to a multi-level lack of mobility of the infant, thus leading to the cranial deformation. Studies show this deformation to be linked with perturbations in various fields.Objective.This study aims to assess the efficacy of osteopathic care on the severity of the PPP.Materials and methods.100 infants were recruited in an osteopathic practice in Lyon (France). All the infants followed the same study protocol; however, the treatment was individualized. Three consultations occurred with a 15 days′ interval over 30 days′ period. Craniometric measurements were realized with Mimos® craniometer on each consultation.Results.The mean severity of the PPP was 10,1 mm at Day 0. At day 30, this average was down to 6 mm. It is a significant (p<0,001) clinical and statistical decrease. Out of the 100 infants, 98 had a decreased deformation while two stagnated.Conclusions.As every infant is unique, every plagiocephaly is different, thus the treatment was not standardised. This study suggest some effectiveness for osteopathic care in the cranial asymmetry of infants with PPP. Other studies should be done, some with a control group, in order to compare our results with spontaneous evolution of plagiocaphaly.

Building a Post Capitalist Economy and Religious Capitalism

This study aims to explore what the post-capitalist economic system and religious capitalism look like. This research also intends to prove whether the post-capitalist economic system and religious capitalism can be applied at this time. Currently, the economic system adopted by most countries in the world is a capitalist economic system. The economic system build by Adam Smith was originally based on religious values. In its journey, it turns out that this system has actually caused many problems, such as inequality of rich and poor, injustice, and even environmental destruction by companies. Facing this reality, some economists have proposed a more humanist and religious system to replace the capitalist economic system. They call this system the post-capitalist economic system and religious capitalism. They consider that capitalism is no longer adequate, especially in the face of a technology that is rapidly developing. Through research using this descriptive method, we look for how to build a post-capitalist economic system and religious capitalism. It is concluded that post-capitalist societies can arise as a result of spontaneous evolution when capitalism is no longer relevant. Post-capitalist societies need new norms and rules in order to run more humanist and religious. The new norms and rules are derived from the universal teachings of religion. Therefore, this economic system is called Religious Capitalism.

Thermal Properties and Key Groups Evolution of Low-Temperature Oxidation for Bituminous Coal under Lean-Oxygen Environment.

To deeply explore the spontaneous combustion disaster of coal caused by air leakage and oxygen supply, low-temperature coal oxidation experiments under different oxygen concentrations (DOC) were carried out. Within the coal spontaneous combustion characteristic measurement system, a synchronous thermal analyzer (STA) and a Fourier transform infrared spectrometer (FTIR), the macro laws of gas and heat generation under DOC are analyzed, and the mechanism of the development of coal spontaneous combustion restricted by the lean-oxygen environment is also revealed. The results show that the change of oxygen concentration (OC) does not affect the critical temperature value and gas index change trend, but the lean-oxygen environment reduces the gas concentration and heat production rate very obviously. According to the temperature of the intersection, OC needs to be lowered to less than 5% when preventing spontaneous combustion of coal. The chain thermal reaction lags in the lean-oxygen environment, and the pyrolysis activity is significantly reduced. Meanwhile, the temperature points at T6 and T7 show significant differences. Furthermore, with increasing OC and temperature, the content of the aliphatic hydrocarbon presents an overall trend of first increasing, then decreasing, and continuously increasing after stage IV. It is concluded that •OH, aliphatic hydrocarbons, aromatic hydrocarbons, and carboxyl groups are the key groups for the coal spontaneous combustion evolution under DOC. To combine the spontaneous combustion reaction of coal in the DOC environment, the reaction path of the index gas in the macroscopic phenomenon and the reason for the concentration differences are revealed, the mechanism for exotherm varies caused by OC is clarified, and the microscopic inhibition affection on the chain reaction within the lean-oxygen environment is also explored. The results put forward the key groups evolution mechanism under the DOC for coal oxidation, which could provide the technical guidance for the fire prevention and control on coal mines.

Coordination‐Induced N−H Bond Splitting of Ammonia and Primary Amine of CuI−MOFs

We report a porous three-dimensional anionic tetrazolium based CuI -MOF 1, which is capable of cleaving the N-H bond of ammonia and primary amine, as well as the O-H bond of H2 O along with spontaneous H2 evolution. In the gas-solid phase reaction of 1 with ammonia and water vapor, CuI -MOF 1 was gradually oxidized to NH2 -CuII -MOF and OH-CuII -MOF, through single-crystal-to-single-crystal (SCSC) structural transformations, which was confirmed by XPS, PXRD and X-ray single-crystal diffraction. Density functional theory (DFT) demonstrated that CuI -MOF could lower N-H bond dissociation free energy of ammonia through coordination-induced bond weakening and promote H2 evolution by the reduction potential of 1. To our knowledge, this is the first example of MOFs that activate ammonia and amine in gas-solid manner.

A FATAL OUTCOME OF A NEONATAL DILATED CARDIOMYOPATHY: EVOLUTIVE NEONATAL LUPUS OR EARLIER CHILDHOOD- ONSET SYSTEMIC LUPUS? A CASE REPORT

Neonatal lupus is a rare congenital syndrome resulting from placental passage of maternal antibodies against SSA/Ro and/or SSB/La to the fetus. It is a generally benign condition, the cardiac involvement determining the prognosis. NNL is rarely manifested by isolated cardiomyopathy. The subsequent evolution towards systemic lupus is rare and unpredictable. We report the case of a daughter from a non-consanguineous marriage with healthy parents who presented a dilated cardiomyopathy in the first months of her life complicated by several outbreaks of heart failure. The spontaneous evolution was marked by the occurrence of skin lesions of the face and arms at the age of 10 years, then by the installation of episodes of hydrous retention at the age of 12 years complicated by an acute renal insufficiency with a rapid fatal outcome at the age of 15 years. ANA antibodies rate was at the threshold of positivity, antiDNA and ANCA were not detectable.C3 rate was low. Although a genetic cause can never be ruled out, the diagnosis was a systemic erythematous lupus SLE (an evolution of an eventual NNL or a childhood-onset systemic lupus). We propose a decision tree for the management of neonatal cardiomyopathy NCMP as a synthesis of the literature.The search for anti SSA/SSB must be part of the check-up usually requested at the time of pregnancy. In addition, we must strengthen the knowledge of the medical profession, especially in the proximity health centers, on rare diseases for a better management of patients.

Fibromatosis Colli: A Review of 4 Cases

Fibromatosis colli is a rare congenital pseudotumor of the sternocleidomastoid muscle, mainly found in the pediatric population. We propose to present four cases diagnosed in the ENT-Neck and head surgery department of the university medical center Mohammed VI in Marrakech, moreover we will recap the management strategy of this entity but also its evolution. We received in the pediatric emergency three infants of 1, 3 and 6 months old and one child of 7 years old, with as a main symptom a painful congenital torticollis. The ultrasound added to our clinical inspection allowed us fairly easily to diagnose the patients. No drug or surgical treatment was prescribed in the infant cases, though surgical treatment was inevitable in the 7 years old patient’s case. During the follow-up, carried out each month, we observed a gradual regression of swelling and torticollis. The prevalence of FC is estimated at 0.3-2% of births. The diagnosis is made at the age of 3 to 4 weeks of life by a thorough inspection of a torticollis associated with a later cervical mass in the framework of a difficult delivery (use of forceps or suction cup). Ultrasonography allows us to diagnose this entity due to the typical aspect of a fusiform thickening of the Sternocleidomastoid muscle. Surgical and medical treatment is rarely useful, and only symptomatic treatment is indicated. The spontaneous evolution of Fibromatosis colli is, even in the absence of treatment, the regression spontaneously in 4 to 6 months. Fibromatosis colli is a relatively rare entity, its frequency in Africa remains to be established, but it is clear that an early diagnosis is key to a speedy recovery.

Graves' Disease during Immune Checkpoint Inhibitor Therapy (A Case Series and Literature Review).

Simple SummaryImmune checkpoint inhibitor (ICPi)-induced thyroid dysfunction is a frequent immune-related adverse event (irAE). ICPi-induced thyrotoxicosis is usually the first stage of a biphasic thyroiditis with secondary hypothyroidism, whereas ICPi-induced Graves’ disease (GD), due to the stimulating activity of TSH-receptor autoantibodies, is extremely rare. The aim of this study was to describe the characteristics and evolution of GD during ICPi therapy. We showed that in five patients with induced GD, two patients evolved into classical GD and the three other patients evolved as thyroiditis with short-term thyrotoxicosis and secondary long-term hypothyroidism, with the initial scintigraphic appearance seeming to predict their evolution. Three other patients had a diagnosis of GD before ICPi treatment: all evolved towards definitive hypothyroidism during treatment, without the appearance of irAE. None of the eight patients developed severe hyperthyroidism with life-threatening symptoms, nor significant Graves’ orbitopathy. Use of ICPis in this population with induced or pre-existing autoimmune GD disease therefore appears to be safe.Thyrotoxicosis is an adverse event associated with immune checkpoint inhibitors (ICPis) that occurs in 0.6 to 3.2% of treated patients, depending on ICPi class. Presentation usually consists of a biphasic thyroiditis with transient thyrotoxicosis and secondary hypothyroidism. ICPi-induced Graves’ disease (GD), due to the stimulating activity of TSH-receptor autoantibodies (TRAb), is extremely rare. The aim of this retrospective study was to describe the characteristics and evolution of GD during ICPi therapy. Five among 243 patients followed for ICPi-induced thyrotoxicosis showed TRAb positivity (2% of the cohort). GD occurred quickly after initiation of ICPis; its course was typical for two patients, with prolonged requirement for antithyroid drug treatment (ATD). The three other patients experienced biphasic thyroiditis with secondary hypothyroidism requiring long-term substitution. Three other patients had a diagnosis of GD before starting ICPis; they evolved toward hypothyroidism with early cessation of ATD and long-term substitution treatment during ICPi treatment. None developed significant Graves’ orbitopathy. ICPi treatment was not interrupted for thyroid dysfunction. In conclusion, GD is a rare, immune-related adverse event of ICPis with an unusual course and frequent evolution to biphasic thyroiditis. In the case of ICPi-induced thyrotoxicosis in the presence of TRAb, observing the spontaneous evolution and performing a scintigraphy are useful before starting ATD treatment. Pre-existing GD is not exacerbated by ICPis and tends to evolve towards hypothyroidism. ICPi treatment can be maintained with adequate biochemical surveillance.

Holmes tremor in a monocentric series of resected brainstem cavernomas

ObjectSeveral scientific papers report clinical symptoms, indications, complications and outcomes of brainstem cavernous malformation (BSCM) surgery without reporting on the occurrence of postoperative Holmes tremor (HT). Our purpose is to report our experience with HT in a monocentric series of resected brainstem cavernomas. MethodsWe reviewed all the BSCM surgical records between 2002 and 2018 at Saint-Luc University Hospital's Department of Neurosurgery, Brussels and selected patients developing HT postoperatively. Patients’ demographics, symptoms, pre- and postoperative imaging, recurrence and complications were analysed. A PubMed literature review was performed to compare our results with those in the existing literature. ResultsIn a total series of 18 resected BSCM, 5 patients: 1 male and 4 females, with a median age of 51 years (range 29–59 years), developed HT. The median preoperative mRS score was 2 (range 1–4). GTR was achieved in all patients without surgery-related death. BSCM were located in the mesencephalon in 4 patients (80%) who developed HT. Tremor was noticed between ten days and one year after surgery. One patient saw significant improvements to the point of stopping treatment. The median follow-up period was 2 years (range 1–14 years). At the last follow-up, 40% of our patients showed a worse mRS score, 40% stayed unchanged, and 20% improved. ConclusionWe are reporting an original single-center series of patients suffering from HT after BSCM surgery. The risk for HT after surgery is significant for midbrain BSCM. A spontaneous favorable evolution is possible.

Oxidation Characteristics of Functional Groups in Relation to Coal Spontaneous Combustion.

To investigate and better understand the mechanism of coal spontaneous combustion, the distributions, evolution, and oxidation characteristics of functional groups in different coal samples were characterized using in situ Fourier transform infrared (FTIR) and electron paramagnetic resonance (EPR) experiments. The macroscopic characteristics of coal spontaneous combustion in relation to functional groups were also analyzed using the thermogravimetric/differential scanning calorimetry–FTIR coupling technique. The experimental results indicated that −OH was the most active groups of coal spontaneous combustion. It not only could react with the absorbed oxygen spontaneously but also found to be the main product of the chemisorption. Consequently, −OH was believed to contribute most both for the loss and increase of coal mass during the process of spontaneous combustion. Aliphatic hydrocarbons were the main components to form −C–O–O• and could be further oxidized into C=O. However, reactions between aliphatic hydrocarbons and oxygen were nonspontaneous. EPR experiments suggested that the tendency of coal spontaneous combustion acutely depended on the stability and survival time of free radicals. The more the stable and longer survival time of free radicals are, the lower the tendency of coal spontaneous combustion is.

Evolutionary game analysis of green industry development in the age of sharing economy

ABSTRACT Sharing economy is also a kind of green economy in essence, which brings opportunities for the development of resource-sharing green industry. By constructing a general evolutionary game model of green industry, the evolutionary stability strategy of green industry system is obtained, and the internal mechanism of the spontaneous evolution of green industry is explained. Furthermore, by comparing the evolutionary game model and numerical simulation results of two green industry development models of factor input and resource sharing in the era of sharing economy, it is found that compared with the factor input development model, the resource-sharing development model is easier to realize the evolutionary game equilibrium between enterprises and consumers. Enriching government subsidies and strengthening consumer guide will help promote the development of resource-sharing green industry.

Iterative Cup Overlapping: An Efficient Identification Algorithm for Cage Structures of Amorphous Phase Hydrates.

Molecular dynamics studies have revealed that the nucleation pathway of clathrate hydrates involves the evolution from amorphous to crystalline hydrates. In this study, complete cages are further classified into the standard edge-saturated cages (SECs) and nonstandard edge-saturated cages (non-SECs). Centered on studying the structure and evolution of non-SECs and SECs, we propose a novel and efficient algorithm, iterative cup overlapping (ICO), to monitor hydrate nucleation and growth in molecular simulations by identifying SECs and discuss possible causes of the instability of non-SECs. Manipulation of topological information makes it possible for ICO to avoid the repeated searches for identified cages and deduce all SECs with low time costs, improving the efficiency of identification significantly. The accuracy and efficiency of ICO were verified by comparing the identification results with other well-proven algorithms. Furthermore, it was found that non-SECs have short lifetimes and eventually decompose or reorganize into more stable structures. Some evidence suggests that the instability of non-SECs is closely related to the hydrogen-bonding configuration of water-ring aggregations that they contain. The spontaneous evolution of the hydrogen-bonding network into the tetrahedral network may be the main factor that causes the conversion of QWRAs and the evolution of non-SECs.

Molecular Dynamics Characterization of Dielectron Hydration in Liquid Water with Unique Double Proton Transfers.

Radiation chemistry of water and aqueous solutions has always been an interesting scientific issue owing to involving electronic excitations, ionization of solvated species, and formation of radiolytic species and many elementary reactions, but the underlying mechanisms are still poorly understood. Here, we for the first time molecular dynamics characterize the hydration dynamics of two correlated electrons and their triggered unique phenomena in liquid water associated with radiolysis of water using the combined hybrid functional and nonlocal dispersion functional. Hydration of two electrons may experience two distinctly different mechanisms, one forming a spin-paired closed-shell unicaged dielectron hydrate (e22-aq) and the other forming a spin-paired metastable open-shell bicaged hydrated electron pair (e-aq···e-aq) which exhibits intriguing antiferromagnetic spin coupling dynamics (in a range of -40 cm-1 to -500 cm-1). e-aq···e-aq can recombine to e22-aq through a unique solvent fluctuation-controlled gradual-flowing mechanism, and enlarging fluctuation can promote the conversion. Interestingly, we directly observe that e22-aq as the precursor can trigger hydrogen evolution via unique continuous spontaneous double proton transfer to the dielectron with a short-lived H-aq intermediate, but e-aq···e-aq does not directly. This is the first direct observation for the connection between e22-aq and spontaneous hydrogen evolution including participation of H-aq in aqueous solution, bridging relevant experimental phenomena. This work also evidences an unnoticed process, the double proton transfer mediated charge separation, and presents the first detailed analysis regarding the evolution dynamics of e22-aq for the understanding of the radiolysis reactions in aqueous solutions.

The Road to Free-Market Family Policy

Author(s): Eichner, Maxine | Abstract: This essay investigates and ultimately rejects the claim that the United States’ comparatively heavily reliance on markets over government to provide the resources that families need is a natural outgrowth of the country’s longstanding veneration of capitalism. In tracing the nation’s economic ideology over time, it demonstrates that, at least until the end of the twentieth century, the constant in US history has not been the expectation of a free-market economy, but rather a commitment to ensuring that the economy, however structured, will enable families to thrive. The dramatic recent shift in economic ideology, when the prevailing commitment to government regulation was superseded by a commitment to free markets, this essay shows, was neither inevitable nor the spontaneous evolution of longstanding free-market ideology. To the contrary, that shift was grounded on the empirically unfounded claim that government support undermined the wellbeing of families. That claim was at least in part developed and popularized by a network of institutions funded by wealthy libertarians seeking to promote an anti-government agenda, and which used racist tropes to increase the resonance of its anti-government message.

Structural Evolution upon Delithiation/Lithiation in Prelithiated Foil Anodes: A Case Study of AgLi Alloys with High Li Utilization and Marginal Volume Variation

AbstractDealloying is a powerful technology to fabricate nanoporous materials with tunable structures and compositions for battery applications. Meanwhile, electrochemical dealloying is an intrinsic process for metal anodes that exhibits fundamental correlations with electrode morphologies and structures. In this work, Li‐Ag composites are fabricated as a case study to understand the spontaneous structural evolution and the in situ formation of nanoporosity during a reversible lithiation/delithiation process. The rationally designed nanoporous AgLi (NPAgLi) framework with limited Li capacity (10 mAh cm−2) enables a dendrite‐free anode with marginal volume variation upon long‐term cycling, which can be attributed to the spatially confined reaction pattern along with efficient Li alloying/dealloying. Furthermore, full cell tests reveal the NPAgLi anode remains stable under practical conditions such as lean electrolyte (15 µL), large areal capacity (1.6 mAh cm−2), and high‐loading cathode (12 mg cm−2). This work provides new perspectives on the in situ structural evolution of Li‐rich alloy electrodes and the results are expected to contribute to the development of alkali metal anodes.

Keep percutaneous approach! Two cases of aortic annular rupture complicating trans catheter aortic valve implantation (TAVI) cured with a second prothesis implantation

Aortic annular rupture is one of the most dramatic complications in TAVI procedures. Emergency surgical treatment has a very high rate of mortality. In our series of 850 TAVI, this complication occurred in 7 cases, with three surgical deaths, one sudden death at day 15 and one less acute case with a spontaneous favourable evolution; the two last cases (occurred in 2018 and 2019) were managed differently. It was two female patients: 86 and 89 years old, with severe and symptomatic aortic stenosis. After discussion with our heart team, TAVI was selected because of age; a femoral access was validated and the aortic area was measured by CT-scan. The valve implantation success was very quickly followed by a severe collapsus, attributed, with cardiac echography, to a cardiac tamponnade. Percutaneous drainage with cell-saver was inefficient to stabilize clinical status. An angiography revealed a contrast extravasation at the level of inferior margin of the prothesis. We opted to a second Edwards Sapien 3 valve and a same size prothesis was implanted in both cases. Clinical amelioration was immediate and durable. The further evolution was uncomplicated. The two patients are still alive and asymptomatic at 24 and 18 months respectively (Fig. 1). In case of annular rupture, probably due to prothesis oversizing (“between two”) or high amount of calcifications, where there is annular dilaceration rather than a clear perforation, surgery has a poor prognosis, because of technical challenges. It seems useful to visualize the annular tear. In our cases, a left ventriculography was very efficient to show it; therefore we decided another valve implantation in order to sealing the rupture. The double skirt of prothesis is probably more effective to cover the fissuration than a very challenging surgical sewing. Faced with this rare but killer complication, second prothesis with skirt could be the first choice, before calling for assistance our surgical colleagues.

ИСТОРИЧЕСКИЕ ФОРМЫ ДЕЯТЕЛЬНОСТИ ЧЕЛОВЕКА КАК ОБЪЕКТ И ПРЕДМЕТ ИССЛЕДОВАНИЯ. ЧАСТЬ 1

In the works of methodologists, less attention is paid to the organization and conduct of specific research projects (R&D), which cannot claim the scope of the subject of the discipline as a whole. Accordingly, the issues of the object and the subject of specific R&D are becoming topical. The accelerating evolution of social objects makes these issues permanently relevant. Inaccuracies in their solution lead to shifts in the content and names of disciplines, inadequacy of the conceptual apparatus, and the complexity of the interaction of scientists working in different scientific traditions. In particular, the name of the discipline «Labor Psychology, Engineering Psychology, Ergonomics» is incorrect. Labor in its initial state is neither an object nor a subject of discipline; psychologists study the characteristics of the subjects of qualified activity and the characteristics of such activity; at present, it is more legitimate to talk about labor activity or, more broadly, about a person's labor activity. Based on the analysis of literary sources, 19 criteria for distinguishing the forms of human activity (labor, physical, etc.) were identified. Considering different types of human activity, it can be stated that they historically change and «crystallize» in a few stable forms. With regard to labor activity, we distinguish three main evolving forms – work, craft, profession (professional activity) and many transitional ones, which stood out and became self-sufficient in different historical periods (about 10000-30000 / 6000-10000 / 800 years ago), in the present coexist in a single spacetime, changing in their proportions. In relation to physical (sports) activity, one can distinguish: physical exercises, «desport» and «wild sports», sports, specialized sports, sports of the highest achievements, which appeared and became dominant in different periods of society development (about 10000-30000 / 300-800 / 150-200 / 70-100 / 50-70 years ago); some of them also coexist in a single space-time, renewing themselves in new variations (children, youth and mass sports, health-improving physical culture, etc.). Similar evolutionary processes take place in other types of human activity – play, learning, etc. The spontaneous evolution of different types of activity (activity), in particular, professional and sports, their subordination to social demand can not always be stated as «progress». The historical evolution of forms of human activity (activity) requires a periodic methodological reflection of the state of the object and the subject of our research.

Quantifying the destructuring of a thixotropic colloidal suspension using falling ball viscometry

The settling dynamics of falling spheres inside a Laponite suspension is studied. Laponite is a colloidal synthetic clay that shows physical aging in aqueous suspensions due to the spontaneous evolution of inter-particle electrostatic interactions. In our experiments, millimeter-sized steel balls are dropped in aqueous Laponite suspensions of different ages (i.e., time elapsed since sample preparation). The motion of the falling balls is captured using a high-speed camera, and the velocities of their centroids are estimated from the images. Interestingly, we observe that balls of larger diameters fail to achieve terminal velocity over the entire duration of the experiment. We propose a mathematical model that accounts for rapid structural changes (expected to be induced by the falling ball) in Laponite suspensions whose aging time scales are much slower than the time of fall of the ball. For a range of ball sizes and Laponite suspension ages, our model correctly predicts the time dependence of the ball velocity. Furthermore, fits to our model allow us to estimate the rates of destructuring of the thixotropic suspensions due to the passage of the falling ball.

Fundamental Properties of Sheared/Guide Field MHD Magnetic Reconnection

Abstract The properties of the sheared/guide field magnetic reconnection (MRX) are investigated with two-dimensional MHD simulation. We simulate the spontaneous evolution from the isothermal current sheet (CS) equilibrium in which distribution of the thermodynamical quantities is symmetric about the CS. The magnetic shear is characterized by two parameters: the shear parameter and the asymmetry parameter. The asymmetry of the Alfvén speed (V A0x) perpendicular to the X-line along the CS is essential. We focus on the asymptotic self-similarly expanding phase of the evolution. This research is unique for the discussion based on the consistency across the entire MRX system, although the sheared MRX has been studied since the early 1980s. In addition to reconfirmation of the previously reported properties of the sheared MRX, the following new properties are found. (1) The reconnection jet changes to the “core–envelope structure” (a high-density core with a low-density envelope) for the sheared symmetric V A0x case but the “two-layered structure” (the high-speed, low-density layer and the medium-speed, high-density layer) for the asymmetric V A0x case. (2) The parameter dependence of the reconnection rate is clarified. The MRX is fastest for the symmetric case and slows as the asymmetry increases for any fixed shear angle. For the symmetric case, the reconnection rate has a monotonically decreasing dependence on the shear angle. (3) In the asymmetric case, the plasmas from both sides of the CS coexist on the same magnetic field lines in the larger V A0x side plasmoid. This characteristic structure suggests an efficient plasma mixing when the plasmoid breaks.

Temperature Gradient Evolution (∆t) and Glycaemia as Complementary Parameters for Diagnosis and Treatment Monitoring of Glucose Metabolism Disorders

Background: Anaesthesia and surgical interventions cause significant changes in body temperature and glycaemia control in human and in animals. Different measures were successfully applied to counter these changes. On the other hand, the treatment of acute or chronic glucose metabolism disorders based only on the evolution of serum glucose is not entirely satisfactory, using a device (ADD/) to measure the evolution of core/ deep and surface body temperatures and their difference (∆t), we investigated the relation between ∆t and glycaemia during anaesthesia in healthy and diabetic animals (rats) and during surgical operations in humans. Therefore, we followed the spontaneous evolution of glycaemia and body temperatures during anaesthesia and surgical stress, with or without interventions (insulin and glucose perfusion) to verify/justify the possibility of the intervention monitoring following ∆t evolution. Methods: Fifty two Wistar rats were used, 26 as controls and 26 with an experimental diabetes induced with streptozotocin to investigate the effect of anaesthesia and surgical stress alone. Another group of 26 Wistar rats were used in the same conditions plus insulin and glucose intravenous injection. The experiments were conducted in standard conditions of room temperature. After anaesthetics administration glycaemia was measured every 15-30min. Deep and superficial temperatures and their difference ΔT were registered continuously using an ADD device. Results: In intact anaesthetized animals after a slight elevation during the first 30 minutes, glycaemia decreased regularly with time during anaesthesia body temperature gradient (∆t) absolute values depended on the position of the temperature sensors and on ambient temperature, but their evolution was the same: slight initial decrease, stabilization and slight elevation before waking. Correlation between the two parameters was not evident. Thoracic surgery caused a more pronounced temperature decrease and glycaemia changes than anaesthesia alone (∆t not measured). In diabetic animals, as a rule glycaemia remained high during the operation time, the variations of ∆t values were more important and prolonged, as a rule ∆t was lower in diabetic animals than in healthy ones. Correlation with glycaemia could not be detected. Comparison between investigation results in animals before and after diabetes induction has pointed the important differences due to the disease and confirmed that ∆t reactions always preceded glycaemia ones) that explain the absence of correlation between these parameters). In all the series anaesthetic overdose could cause a temporary negative ∆t even in presence of normo- or hyperglycaemia. Ambient temperature elevation >30°C during the sessions caused an increase of all investigated features absolute values but none of their evolution. Taking into account the quick reaction of ∆t to modifications of external and internal conditions, monitoring glycaemia disorders by balanced insulin and glucose intravenous injection guided by ∆t evolution was tried with positive encouraging results. Clinical observations were added which results were close to the experimental ones, as well when concerning the influence of external (temperature) and internal (anaesthesia), metabolic factors, as when confirm possibility of monitoring insulin administration with energetic feedback. Conclusion: This study confirms that stress, ambient temperature and anaesthesia can alter both glycaemia and body temperature evolution, and that more profoundly in diabetes. It has shown a high sensibility of ∆t to the metabolic changes due to these factors. It ought to allow a valuable algorithm elaboration for glucose and insulin administration in automatic monitoring of energetic balance by a new ADD-CIGT device.