Secondary Mechanisms Research Articles

Realistic frontal face reconstruction using coupled complementarity of far-near-sighted face images

There is still a huge gap in the accuracy of face recognition in public video surveillance scenarios. The far-sighted low-resolution (LR) frontal faces have holistic facial profiles but lack sufficient clearness, while the near-sighted high-resolution (HR) tilted faces show rich facial details yet incomplete facial structure suffering from the overhead self-occlusion of the head blocking the face. Following this observation, this paper proposes a dual-branch HR frontal face reconstruction network to explicitly exploit such coupled complementarity hidden in the far-near face images of the same subject, where one branch performs super-resolution (SR) of the LR frontal face and the other branch performs detail fusion and holistic compensation between multiple HR tilted faces as well as the super-resolved frontal result. In particular, we propose a secondary relevance attention mechanism to enhance the embedding of key features, which sequentially performs rough and precise feature matching and embedding, thus enabling coarse-to-fine progressive compensation. Further, scale-entangled densely connected blocks (SEDCB) are used to gradually integrate the relevance information at different scales (due to the different sighting distances) to promote the information interaction between the features of tilted faces. Besides, we also propose a ternary coupled sample pair (LR far-sighted frontal face, HR near-sighted tilted face, normal ground truth clear face) training scheme to supervise the network optimization. Extensive experimental results on two real-world tilt-view face datasets show that our method can not only reconstruct more realistic HR frontal faces but also facilitate the down-stream face identification task compared with the competing counterparts.

Positive Torque Modulation Method and Key Technology of Conventional Beam Pumping Unit

The large fluctuation of net torque and the existence of negative torque on the crank output shaft of the beam pumping unit are the decisive factors leading to its low efficiency and high energy consumption. The conventional pumping unit CYJ10-4.2-53HF was selected as the study object on the basis of the fixed shaft secondary balance principle and the positive torque modulation scheme was first proposed according to the following secondary balance principle based on the linkage. The kinematics analysis of the suspension point and the secondary incremental velocity mechanism were carried out using the theory of rigid body plane kinematics. The force analysis of each moving part of the pumping unit was carried out, the net torque expression of the crank output shaft was obtained, and an example calculation was performed. The positive torque beam pumping unit was developed and tested in a field test. The tests showed that the positive torque beam pumping unit was able to fully realize positive torque operation under field well conditions, with a power saving rate of 23.73% and a 14.5% increase in system efficiency, and that the reliability of the pumping unit meets the requirements for field application.

Reaction Mechanisms of Histidine and Carnosine with Hypochlorous Acid Along with Chlorination Reactivity of N-Chlorinated Intermediates: A Computational Study.

Hypochlorous acid (HOCl) released from activated leukocytes not only plays a significant role in the human immune system but is also implicated in numerous diseases including atherosclerosis and some cancers due to its inappropriate production. Histidine (His) and carnosine (Car), as a respective mediator and protective agent of HOCl damage, have attracted considerable attention; however, their detailed reaction mechanisms are still unclear. In this study, using a His residue with two peptide bond groups (HisRes) as a model, the reaction mechanisms of HisRes and Car including NεH and NδH tautomers with HOCl along with the chlorination reactivity of N-chlorinated intermediates were investigated by quantum chemical methods. The obtained results indicate that in the imidazole side chain, the pyridine-like N is the most reactive site rather than the pyrrole-like N, and the kinetic order of all of the possible reaction sites in HisRes follows pyridine-like N > imidazole Cδ ≫ imidazole Cε > pyrrole-like N, while that in Car is pyridine-like N ≫ imidazole Cδ ≫ amide N. As for N-chlorinated intermediates at imidazole, although the unprotonated form has a low chlorination reactivity as expected, it can still chlorinate tyrosine. Especially, the protonated form exhibits similar ability to HOCl, causing secondary damage in vivo. N-Chlorinated Car features higher internal chlorine migration ability than its intermolecular transchlorination, preventing further HOCl-induced damage. Additionally, a generally overlooked nucleophilic Cl- shift is also found in N-chlorinated Car/HisRes, indicating that nucleophilic sites in biomolecules also need to be considered. The outcomes of this study are expected to expand our understanding of secondary damage and protective mechanisms involved in HOCl in humans.

Current status and development direction of hyperbaric medicine in Korea

Background: The indications of hyperbaric oxygen therapy (HBOT) covered by the health insurance in Korea increased to 16 in 2019, which includes acute central retinal artery obstruction within 24 hours of vision loss; anemia due to excessive bleeding, since blood transfusion is impractical; chronic refractory osteomyelitis (Wagner grade ≥3); and intracranial abscess.Current Concepts: HBOT affects the treatment in the primary and secondary mechanisms. According to the Boyle’s law, the primary mechanism is important in treating decompression sickness and intravascular air embolism by decreasing the volume of air bubbles when pressure increases, whereas the secondary mechanism involves hyperoxygenation of the primary mechanism and various effects, such as vasoconstriction, angiogenesis, immune function enhancement, reperfusion injury prevention, antimicrobial action, and gas washout effect, occur. In the past 5 years, domestic HBOT has made significant progress. However, there are many non-therapeutic lowpressure HBOT facilities that are limited by insurance coverage issues, quality equipment management, and medical personnel in HBOT facilities.Discussion and Conclusion: To solve the problem, the introduction of the definition of therapeutic hyperbaric pressure and certification system of HBOT facilities must be initiated. Moreover, the system should be improved so that insurance can be applied for a more indication of HBOT.

Metabolic Syndrome and β-Oxidation of Long-Chain Fatty Acids in the Brain, Heart, and Kidney Mitochondria.

We present evidence that metabolic syndrome (MetS) represents the postreproductive stage of the human postembryonic ontogenesis. Accordingly, the genes governing this stage experience relatively weak evolutionary selection pressure, thus representing the metabolic phenotype of distant ancestors with β-oxidation of long-chain fatty acids (FAs) as the primary energy source. Mitochondria oxidize at high-rate FAs only when succinate, glutamate, or pyruvate are present. The heart and brain mitochondria work at a wide range of functional loads and possess an intrinsic inhibition of complex II to prevent oxidative stress at periods of low functional activity. Kidney mitochondria constantly work at a high rate and lack inhibition of complex II. We suggest that in people with MetS, oxidative stress is the central mechanism of the heart and brain pathologies. Oxidative stress is a secondary pathogenetic mechanism in the kidney, while the primary mechanisms are kidney hypoxia caused by persistent hyperglycemia and hypertension. Current evidence suggests that most of the nongenetic pathologies associated with MetS originate from the inconsistencies between the metabolic phenotype acquired after the transition to the postreproductive stage and excessive consumption of food rich in carbohydrates and a sedentary lifestyle.

Experimental investigation on Mode I crack growth and damage mechanism of sandstone subjected to cyclic loading

To further investigate the Mode I crack growth and damage mechanism, compression tests were performed on notched semi-circular bending (NSCB) specimens at different cycle amplitudes. The crack propagation gauge and digital image correlation (DIC) recorded the entire process of crack growth. The real-time crack growth rate and evolution of the horizontal strain field during crack growth were obtained. Based on the crack growth rate, the crack growth process can be divided into three stages: the cracking latent period (primary stage), stable crack growth stage (secondary stage), and accelerated crack growth stage (tertiary stage). The cracking latent period accounts for a large proportion of the entire crack growth. The stable crack (i.e., steady subcritical crack growth) expanded slowly to a certain extent after initiation, and then the accelerated crack growth led to failure. With the increase in the cyclic amplitude, the cracking latent period is shortened and the crack growth rate is accelerated. The crack growth rate is positively correlated with the stress intensity factor. Moreover, scanning electron microscopy (SEM) was used to analyse the development of the fracture process zone (FPZ) and the subcritical crack damage mechanism. The SEM images showed two damage phenomena: (1) intergranular cracks caused by grain debonding (primary mechanism) and (2) transgranular cracks (secondary mechanism).

Study of the secondary droplet breakup mechanism and regime map of Newtonian and power law fluids at high liquid–gas density ratio

This work reports the numerical investigation of the secondary breakup of non-Newtonian droplets at different Weber Weg and Ohnesorge Ohl numbers. As part of this work, an in-house coupled level set volume of fluid solver is developed based on OpenFOAM libraries. It uses improved curvature calculation techniques like smoothening and the closest point search method. Flow is assumed to be axisymmetric. Approximately 95 different cases were simulated to investigate the effect of Weg and Ohl numbers on secondary breakup for Newtonian, shear-thinning, and shear-thickening fluids. Ohl varies from 10−3 to 101, and, correspondingly, Weg varies from 101 to 103. The non-Newtonian rheology is modeled as a power-law fluid, and the power-law index n ranged from 0.2–1.8. The present work describes the flow field near the droplet and the effects of non-Newtonian parameters and viscosity on the flow field. The various aspects of droplet dynamics like droplet deformation ratio y, deformation rate ẏ, and coefficient of pressure Cp are studied and compared with the internal flow theory. A generalized relation for critical Weber number Weg,cr is proposed for both Newtonian and non-Newtonian fluids and is shown in a phase diagram plot to map the different regimes of secondary droplet breakup.

Localization of Multi-Lamellar Vesicle Nanoparticles to Injured Brain Tissue in a Controlled Cortical Impact Injury Model of Traumatic Brain Injury in Rodents.

Severe traumatic brain injury (TBI), such as that suffered by patients with cerebral contusion, is a major cause of death and disability in young persons. Effective therapeutics to treat or mitigate the effects of severe TBI are lacking, in part because drug delivery to the injured brain remains a challenge. Promising therapeutics targeting secondary injury mechanisms may have poor pharmacokinetics/pharmacodynamics, unwanted side effects, or high hydrophobicity. To address these challenges, we have developed a multi-lamellar vesicle nanoparticle (MLV-NP) formulation with a narrow size distribution (243 nm in diameter, 0.09 polydispersity index) and the capability of encapsulating hydrophobic small molecule drugs for delivery to the injured brain. To demonstrate the utility of these particles, we produced dual-fluorescent labeled nanoparticles containing the organic dyes, coumarin 153 and rhodamine B, that were delivered intravenously to Sprague-Dawley rats and C57Bl6/J mice at 1, 1 and 4, 24, or 48 h after controlled cortical impact injury. Distribution of particles was measured at 5, 25, 48, or 49 h post-injury by fluorescence microscopy of coronal brain sections. In all cases of MLV administration, a 1.2- to 1.9-fold enhancement of ipsilateral fluorescence signal was observed compared to the contralateral cortex. Enhanced fluorescence was also observed in the injured hippocampal tissue in these animals. MLV-NPs administered at 1 h were observed intracellularly in the injured hemisphere at 48 h, suggesting the possibility of concentrated drug delivery to injured cells. These results suggest that MLV-NP delivery of therapeutic agents may be a viable strategy for treating cerebral contusion TBI.

The formation mechanism of micro-nano secondary phase in solid-liquid doped TZM alloy

Among the various secondary phases distributed in the TZM (Titanium-Zirconium-Molybdenum) alloy matrix, the ones that can play a strengthening role are often those with a particle size smaller than 1 μm. In this study, titanium sulfate, zirconium nitrate, and fructose were used as raw materials. The TZM alloy with uniform distribution and an average secondary phase particle size of 940 nm (hereinafter referred to as MN-TZM alloy) was prepared through a solid-liquid doping preparation process. The thermodynamic calculation reveals the formation mechanism of the micro-nano-level secondary phase in the MN-TZM alloy. Thermogravimetric analysis (TG-DSC, TG-MS) and transmission electron microscope (TEM) confirmed the calculation results. The generation process of the micro-nano secondary phase evolution can be divided into four parts. The first stage is the process of solute dissolution at room temperature. In the second stage, doping and drying process take place below 100 °C. Third, reduction and secondary phase precursor incubation processes occur from 100 to 700 °C. Fructose decomposes (100 °C) to obtain organic carbon and water. The decomposition of zirconium nitrate (100 °C) yields NH 3 , H 2 O, ZrO 2 and Zr, while the titanium sulfate decomposes directly at 200– 242 °C to obtain SO 2 , H 2 O, TiO 2 and Ti. In the last stage, the secondary phase nucleates and grows up (700– 1800 °C). A large variety of micro-nano-scale and even nano-scale secondary phase particles have been discovered, including TiO 2 , ZrO 2 , ZrC and TiC. These observations provide necessary information for tracing back the secondary phase precipitation mechanism in the manufacturing process of high-performance molybdenum alloys. • The average grain size of MN-TZM alloy is 940 nm. • The micro-nano secondary phase reduces the average grain size of TZM alloy by 26%. • TZM alloy was prepared from titanium sulfate, zirconium nitrate, fructose and molybdenum powder for the first time. • The formation mechanism of micro-nano secondary phase in TZM alloy was clarified.

Stereotactic Vacuum-Assisted Minimally Invasive Aspiration of Hemorrhagic Stroke.

Intracerebral hemorrhage (ICH), accounting for 9-27% of all strokes, carries substantial rates of morbidity and mortality that have not shown much improvement in the past decades. The poor outcomes of ICH can be attributed to the primary and secondary brain injuries caused by mass effects and inflammatory mechanisms, respectively. Early ICH evacuation is a critical component of treatment, as it mitigates the effect of both the primary and secondary mechanisms of brain injury and is associated with significant improvement in patient outcomes. However, no standardized evacuation technique exists. This technical report introduces a novel stereotactic vacuum-assisted minimally invasive (MIS) aspiration of a hemorrhagic stroke with its effectiveness evidenced by excellent patient recovery.

Practical Considerations for Continuous Time-Domain Cerebrovascular Reactivity Indices in Traumatic Brain Injury: Do Scaling Errors in Parent Signals Matter?

Literature pertaining to traumatic brain injury care involves the mediation and control of secondary brain injury mechanisms, chief among these is cerebral autoregulation. Cerebral autoregulation is frequently assessed through surrogate measures of cerebrovascular reactivity. An important aspect to acknowledge when calculating cerebrovascular reactivity indices is the linearity within two-parent bio-signals or variables. We highlighted the concept of linearity in raw parent bio-signals used for the calculation of the cerebrovascular reactivity index and what potential implications linearity carries for index derivation. Key of which is that the initial differencing or location of the pressure probes does not influence linear methods of cerebral reactivity calculations so long as the slow-wave vasogenic changes are being recorded.

CDK6 Degradation Is Counteracted by p16INK4A and p18INK4C in AML.

Simple SummaryCDK4/6 kinase inhibitors show promising results in various subtypes of AML, which has been primarily assigned to the inhibition of CDK6. To bypass therapeutic resistances and tackle the kinase-dependent, as well as kinase-independent, functions of CDK6, new CDK6 degraders have been developed. Here, we present insights into the mechanistic requirements for the efficacy of a CDK6-specific degrader in AML. We show that the presence and levels of the INK4 proteins p16INK4A and p18INK4C determine the extent of CDK6 degradation. Our study reveals the importance of INK4 protein levels as predictive markers for CDK6-targeted therapy in AML.Cyclin-dependent kinase 6 (CDK6) represents a novel therapeutic target for the treatment of certain subtypes of acute myeloid leukaemia (AML). CDK4/6 kinase inhibitors have been widely studied in many cancer types and their effects may be limited by primary and secondary resistance mechanisms. CDK4/6 degraders, which eliminate kinase-dependent and kinase-independent effects, have been suggested as an alternative therapeutic option. We show that the efficacy of the CDK6-specific protein degrader BSJ-03-123 varies among AML subtypes and depends on the low expression of the INK4 proteins p16INK4A and p18INK4C. INK4 protein levels are significantly elevated in KMT2A-MLLT3+ cells compared to RUNX1-RUNX1T1+ cells, contributing to the different CDK6 degradation efficacy. We demonstrate that CDK6 complexes containing p16INK4A or p18INK4C are protected from BSJ-mediated degradation and that INK4 levels define the proliferative response to CDK6 degradation. These findings define INK4 proteins as predictive markers for CDK6 degradation-targeted therapies in AML.

Primary versus secondary infrastructure capacity allocation mechanisms

Many infrastructure systems are governed by non-monetary capacity allocation: users submit scheduling requests and an infrastructure manager determines a schedule of utilization given capacity restrictions. Two broad approaches exist to cope with information asymmetry. Under a primary mechanism, the infrastructure manager determines the eventual schedule. Under a secondary mechanism, users can swap their service units following the scheduling adjustments from the infrastructure manager. The secondary mechanism provides flexibility to align the schedule with users’ (private) preferences. However, this paper shows that the secondary mechanism may not result in more efficient outcomes when users are strategic. We develop a multi-stage capacity allocation game in infrastructure systems characterized by multi-period operations, discrete service units and non-atomistic users. We show that the primary mechanism either is incentive compatible, or incentivizes users to voluntarily displace low-value service units from peak to off-peak periods. Such “good gaming” behaviors mitigate system-wide costs. In contrast, the secondary mechanism incentivizes users to request more service units than preferred in peak periods. Such “bad gaming” behaviors increase system-wide costs. The costs from “bad gaming” may outweigh the benefits from secondary swaps: system-wide costs can be lower under the (restricted) primary mechanism than under the (flexible) secondary mechanism.

Paroxysmal sympathetic hyperactivity following acute diffuse brain swelling due to traumatic brain injury: a case report with good clinical outcome

BackgroundParoxysmal sympathetic hyperactivity (PSH) may occur after acquired brain injury. The clinical presentation of PSH results from increased sympathetic overdrive, including transient paroxysms of tachycardia, hypertension, hyperventilation, hyperthermia, dystonic posturing, and excessive sweating. The exact pathophysiology of PSH, however, remains unclear, and no definitive treatment is available. Herein, the authors report a case of PSH in a male patient who experienced acute brain swelling after acquired head injury, for which a good clinical outcome was achieved due to multimodal treatment. The ensuing discussion also addresses the pathophysiology of PSH.Case presentationAn 18-year-old man was transported to the authors’ hospital after experiencing a traumatic brain injury. On admission, computed tomography revealed cerebral herniation due to diffuse brain edema in the left parietal lobe. Emergency decompressive craniotomy and internal decompression were performed. After surgery, anti-edema therapy (glycerol and mannitol) was continued. Ten days postoperatively, PSH was diagnosed in accordance with the PSH assessment score (20 points). Vecuronium, fentanyl, morphine, propofol, dexmedetomidine, and a calcium channel blocker were administered; however, the drug effect was insufficient. Thirty-two days postsurgery, the patient gradually recovered from the adrenergic symptoms of PSH, and head computed tomography performed 32 days after surgery revealed improvement in diffuse brain edema. Ultimately, the patient fully recovered and lived independently at home.ConclusionsConsidering the pathophysiology of PSH, cerebral contusion, acute brain swelling, and secondary mechanisms of brain injury may trigger sympathetic nerve-enhancing regions and cause hyperexcitation of the sympathetic nervous system, resulting in PSH. The outcome of the present case demonstrates that PSH can be reversed if it is identified early and before it becomes irreversible, that is, post the development of hypoxic encephalopathy or widespread brain damage. Appropriate management, including decompression craniotomy for brain swelling and multidisciplinary treatment, leads to good clinical outcomes.

Analysis of secondary emission mechanism in electron avalanches propagating in cylindrical nanoruptures in liquid water

Recently, a bouncing-like mechanism for electron multiplication inside long nano-ruptures during the early stages of nanosecond discharge in liquid water has been proposed in (Bonaventura 2021 Plasma Sources Sci. Technol. 30 065023). This mechanism leads to the formation of electron avalanches within nano-ruptures caused by strong electrostrictive forces. The avalanche propagation is a self-sustaining process: the electrons emitted from the water surface to the cavity support the propagation of the avalanche and the avalanche itself is a source of the parent electrons impinging on the surface of the nano-rupture and causing secondary emission. We analyze the process of the electron secondary emission directly from the simulation results of the electron avalanche propagation. This allow us to perform an in situ study of the secondary emission and related physical processes. We present the results of an extensive parametric study performed using the state-of-the-art simulation toolkit Geant4-DNA for modeling electron-liquid water interactions. It is shown that the typical lifetime of an electron in an avalanche is about 0.1 to 0.2 picoseconds and that the electron experiences about 4 bounces before ending up in liquid water. In addition, it is shown that the secondary electrons are formed in a layer adjacent to the nano-rupture surface that is only a few nanometres thin. The secondary electron velocity distribution at the moment of the electron birth, the velocity space of electrons (re-)emitted from the water, and the velocity space of electrons at the moment of their impact to the cavity surface are analyzed in detail. Electron bouncing and secondary electron generation efficiency are quantified using the secondary emission coefficient, the secondary emission efficiency, and the effective energy consumed to produce new electrons.

Secondary Crystallization Mechanism of Nanocrystalline Induced by Mechanical Ball Milling in Borosilicate Glass

Herein, we first prepared polychromatic self-crystallized CsPb(Cl/Br/I)3 perovskite nanocrystalline (PN) borosilicate glass by the high-temperature melting method. Then, the PN glass is exposed to frequent mechanical ball milling. Due to the high-energy mechanical force, the microstructure changes in borosilicate glass such as topological structure, chemical short-range order, and atomic rearrangement lead to the secondary crystallization of PN on the glass surface. Hence, the photoluminescence quantum yield (PLQY) of CsPbBr3 PN glass has enhanced 120 times and that of CsPbBrI2 PN glass has enhanced 74 times. Moreover, the prepared highly luminescent CsPbBr3 PN glass has extremely large exciton binding energy (468 meV), which shows good thermal stability. Finally, by embedding the prepared PN glass powder in the polydimethylsiloxane matrix, multicolor luminescent flexible films are constructed, presenting application prospects in the flexible display field. This work deepens the understanding of how the microstructure change in glass influences the crystallization behavior of PN and resolves the challenge that PN glass cannot have high PLQY and stability at the same time.

Relationship Between White Matter Lesions and Gray Matter Atrophy in Multiple Sclerosis: A Systematic Review.

Background and ObjectivesThere is currently no consensus about the extent of gray matter (GM) atrophy that can be attributed to secondary changes after white matter (WM) lesions or the temporal and spatial relationships between the 2 phenomena. Elucidating this interplay will broaden the understanding of the combined inflammatory and neurodegenerative pathophysiology of multiple sclerosis (MS), and separating atrophic changes due to primary and secondary neurodegenerative mechanisms will then be pivotal to properly evaluate treatment effects, especially if these treatments target the different processes individually. To untangle these complex pathologic mechanisms, this systematic review provides an essential first step: an objective and comprehensive overview of the existing in vivo knowledge of the relationship between brain WM lesions and GM atrophy in patients diagnosed with MS. The overall aim was to clarify the extent to which WM lesions are associated with both global and regional GM atrophy and how this may differ in the different disease subtypes.MethodsWe searched MEDLINE (through PubMed) and Embase for reports containing direct associations between brain GM and WM lesion measures obtained by conventional MRI sequences in patients with clinically isolated syndrome and MS. No restriction was applied for publication date. The quality and risk of bias in included studies were evaluated with the Quality Assessment Tool for observational cohort and cross-sectional studies (NIH, Bethesda, MA). Qualitative and descriptive analyses were performed.ResultsA total of 90 articles were included. WM lesion volumes were related mostly to global, cortical and deep GM volumes, and those significant associations were almost without exception negative, indicating that higher WM lesion volumes were associated with lower GM volumes or lower cortical thicknesses. The most consistent relationship between WM lesions and GM atrophy was seen in early (relapsing) disease and less so in progressive MS.DiscussionThe findings suggest that GM neurodegeneration is mostly secondary to damage in the WM during early disease stages while becoming more detached and dominated by other, possibly primary neurodegenerative disease mechanisms in progressive MS.

Effect of Bound Water Content on Secondary Compression of Three Marine Silty Clays

Secondary compression studies can provide insights for evaluating the engineering potential and environmental impact of soil. The objective of this research was to investigate the effect of bound water content on the secondary compression of marine silty clay. To this end, a novel method was established based on thermogravimetric analysis (TGA) to determine the contents and limits of strongly bound water and weakly bound water for three typical marine silty clays including Tianjin mucky silty clay (TJ), Qingdao mucky silty clay (QD), and Weihai silty clay (WH). A total of 17 groups of uniaxial confined compression tests were performed for reconstituted samples at different absolute water contents under the condition of multistage loading to investigate their secondary compression characteristics. The results show that the initial dehydration temperature of strongly bound water (Ts) corresponds to the peak of the derivative thermogravimetry (DTG) curve. The values of Ts for TJ, QD and WH are 112.35 °C, 109.67 °C and 118.46 °C, respectively. The initial dehydration temperatures of weakly bound water (Tw) for TJ, QD and WH are 55.26 °C, 52.56 °C and 56.56 °C, respectively. The secondary compression coefficient Cα changes little before the strongly bound water limit and increases dramatically as weakly bound water content increases at the same vertical stress. A piecewise linear model and a quadratic polynomial model are established for calculating the average secondary compression coefficient from bound water content. Weakly bound water is the determining factor controlling secondary compression. Increasing the bound water content weakens the connection force and friction force among the particles and the viscosity of weakly bound water. The results will guide decisions on long-term settlement assessment and facilitate understanding of the secondary compression mechanism of marine silty clays affected by bound water.

Characteristics and Source Analysis of Water-soluble Inorganic Pollution in PM2.5 During Summer in Central China

In order to investigate the pollution characteristics and sources of water-soluble ions in atmospheric PM2.5 in different regions of central China during summer, Wuhan, Suizhou, and Pingdingshan were selected as urban, suburban, and rural monitoring stations, respectively, to collect PM2.5 samples, and the mass concentration of PM2.5 in the atmosphere and the contents of eight water-soluble ions were analyzed. The results showed that ρ(water-soluble ions) at the three sites showed obvious spatial distribution characteristics, with Pingdingshan[(36.29±9.82) μg·m-3] > Wuhan[(32.55±10.05) μg·m-3] > Suizhou[(26.10±6.23) μg·m-3], accounting for 52.47%, 51.32%, and 48.61% of the PM2.5 mass concentration, respectively. In the Pingdingshan station, the proportion of water-soluble ions was the largest due to biomass combustion in the rural area. Additionally, SNA (SO42-, NO3-, and NH4+) were the main ionic components, accounting for 95.65%, 96.12%, and 97.33% of the total water-soluble ions, respectively. The mean values of SOR of the Wuhan (0.64) and Suizhou (0.63) stations were higher than that of the Pingdingshan station (0.50), whereas the NOR values of the Wuhan (0.18) and Pingdingshan (0.19) stations were higher than that of the Suizhou station (0.15). The difference in SOR and NOR among stations was affected by the secondary conversion mechanism, the ammonia-rich environment, and the surrounding traffic sources, respectively. The PM2.5 at the Wuhan and Pingdingshan stations was in general alkaline, whereas at the Suizhou station it was neutral or weakly acidic, which was mainly caused by differences in NH4+. NH4+ mainly existed in the form of (NH4)2SO4 and NH4NO3 at the Wuhan and Pingdingshan stations, whereas at the Suizhou station it mainly existed in the form of (NH4)2SO4 or (NH4)HSO4. PCA-MLR analysis revealed that the Wuhan (89.27%) and Suizhou (67.38%) stations were the most affected by secondary conversion sources, whereas the Wuhan station was also affected by industrial sources (8.54%) and coal sources (2.27%). The pollution sources of the Suizhou station also included biomass combustion (24.42%) and dust sources (8.25%). The Pingdingshan station was most affected by biomass combustion (58.37%), followed by dust and combustion sources (38.05%) and traffic sources (3.58%). The analysis of potential sources of SNA (PSCF) showed that the main potential source areas of Wuhan were the boundary of Hubei, Henan, and Anhui and the southwest area of Anhui. Suizhou and Pingdingshan were affected by long-distance transport, and the main potential source regions were distributed in Shanghai, Jiangsu, and Anhui provinces from the east coast to the west.

Early predictors of systolic right ventricular dysfunction in the diagnostic algorithm in young patients with pulmonary sarcoidosis

Abstract Funding Acknowledgements Type of funding sources: None. Sarcoidosis can affect not only the lungs, but also the heart, particularly, the right ventricle (RV), by both primary (5-25% of patients) or secondary mechanism due to PH. People of young, working age are at higher risk. Purpose to study global longitudinal strain (GLS), RV ejection fraction in 3D mode (EF-3D), TAPSE and S", pulmonary artery systolic pressure (SPAP) at rest and at peak of exercise in patients with sarcoidosis and to determine the role of these parameters in diagnostic algorithm. Methods. The main group consisted of 66 patients with histologically confirmed stage I-II pulmonary sarcoidosis: 42 men (63.6%) and 24 women (36.4%); mean aged 31.9 ± 5.59 years. The control group included 33 healthy, nonsmoking people: 24 men (72.7%) and 9 women (27.3%); mean aged 30.18 ± 5.3 years. Results. There were no deviations from the normal values of S’and TAPSE at rest, as well as at rest at the peak of exercise in both groups (p> 0.05). EF-3D RV was within the normal values and didn’t differ significantly at rest and at the peak of exercise (p > 0.05). RV GLS in both groups at rest and at the peak of exercise, were also normal. RV GLS in patients with sarcoidosis during exercise didn"t increase, but decreased (p = 0.004): from -22.8 ± 3.4% at rest to -21.2 ± 4.7% at the peak of exercise, by 7% (in control group: -24.1 ± 2.7 to -25.1 ± 3, p = 0.002). Values of SPAP at rest in patients with sarcoidosis was slightly higher than in healthy individuals (28.5 ± 8.3 and 24.8 ± 5.21 mm Hg; p = 0.03), in normal ranges. At the peak of exercise SPAP in patients with sarcoidosis increased greater than in the control group (32.9 ± 10.1 and 48.36 ± 14.4 mm Hg; p = 0.000001). In the control group at rest, the upper quartile of the SPAP was 29 mm Hg, at the peak of exercise - 38 mm Hg. In the main group, these indicators were significantly higher: 35 and 62 mm Hg. In the main group, at the peak of exercise, the SPAP value exceeded the upper quartile of the control group (38 mm Hg) in 79% of cases. These data may indicate the presence of subclinical pulmonary hypertension in the main group. To determine the border of normal and pathology in study groups, the threshold values of the RV GLS were obtained at the peak of exercise by the method of constructing classification trees. For RV GLS at the peak of exercise, this value turned out to be -21.6%. This means that when RV GLS is less than -21.6% in young patients with pulmonary sarcoidosis, the likelihood of subclinical RV dysfunction is 90%. In combination with an increase in SPAP at the peak of exercise more than 39.5 mm Hg these patients have an even higher rank of the significance of RV dysfunction, namely 100%. So, we propose to complete the diagnostic algorithm in patients with pulmonary sarcoidosis by RV GLS SPAP at the peak of exercise for defining the early RV systolic disfunction.