ABSTRACT
Frequent oil spills and the discharge of oily wastewaters have caused a serious threat to the environment, ecosystems, and human beings. Herein, a photothermal and superhydrophobic melamine sponge (MS) decorated with MXene and lignin particles has been prepared for the separation of oil/water mixtures, the recovery of crude oils, and active deicing. The obtained superhydrophobic melamine sponge shows a water contact angle (WCA) of 152.3° and an oil contact angle of â¼0° and possesses good chemical stability, thermal stability, and mechanical durability in terms of being immersed in various liquids (i.e., corrosive solutions, organic solvents, and boiling water) and being abrased by sandpapers. This superhydrophobic MS displays a high oil adsorption capacity of CCl4, up to 91.6 times its own weight and a high separation efficiency of 99.4%. Furthermore, the maximum surface temperature of the superhydrophobic MS reaches 57.5 °C under sunlight irradiation (1.0 kW/m2) due to the excellent photothermal heating conversion performance of MXene and lignin particles. When exposed to sunlight, the superhydrophobic MS can quickly absorb viscous crude oils up to 72 times its own weight. Also, the WCA of the superhydrophobic MS remains above 146° after 50 icing/deicing cycles, showing excellent photothermal anti-icing properties. Thus, this study presents an easy and low-cost method for designing photothermal superhydrophobic melamine sponges and opens a new avenue to the applications of efficient oil/water separation, fast crude oil recovery, and active deicing.
ABSTRACT
A novel copper-catalyzed cyclization reaction for the synthesis of pyrazolo[1,5-a]quinoline, triazolo[1,5-a]quinoline, and pyrrolo[1,2-a]quinoline derivatives is described. The process is initiated by di-tert-butyl peroxide-mediated C(sp3)-H activation to generate the α-functionalized radical, which supervenes a cascade radical addition/cyclization sequence to access the N-fused quinolines in good yields with broad functional group tolerance.
ABSTRACT
Metal-organic frameworks (MOFs) with porosity and functional adjustability have great potential for the removal of organic dyes in the wastewater. Herein, an anionic porous metal-organic framework (MOFs) [Me2NH2]2In2[(TATAB)4(DMF)4]·(DMF)4(H2O)4 (HDU-1) was synthesized, which is constructed from a [In(OOC)4]- cluster and a nitrogen-rich linker H3TATAB (4,4',4â³-s-triazine-1,3,5-triyltri-p-aminobenzoic acid). The negatively charged [In(OOC)4]- cluster and uncoordinated -COOH on the linker result in one unit cell of HDU-1 having 8 negative sites. The zeta potential of -20.8 mV dispersed in pure water also shows that HDU-1 possesses negatively charged surface potential. The high electronegativity, water stability, and porosity of HDU-1 can facilitate the ion-exchange and Coulombic interaction. As expected, the HDU-1 exhibits high selectivity and removal rates towards trace cationic dyes with suitable size, such as methylene blue (MB) (96%), Brilliant green (BG) (99.3%), and Victoria blue B (VB) (93.6%).
Subject(s)
Coloring Agents , Metal-Organic Frameworks , Indium , Porosity , Nitrogen , Water , Cations , AdsorptionABSTRACT
BACKGROUND: The Alphapapillomavirus 9 (α-9 HPV) is a member of the Alphapapillomavirus genus and Papillomaviridae family. These viruses are almost all carcinogenic HPV, which is closely related to 75% of invasive cervical cancer worldwide, and has a high prevalence in Sichuan. The carcinogenic function is mainly realized by its E6 oncoprotein. METHODS: Cell samples were collected by cervical scraped for HPV detecting and typing. HPV-16, HPV-31, HPV-33, HPV-52, HPV-58 5 α-9 genus HPV subtype positive samples were selected, their E6 gene was sequenced and analyzed. The positive selection sites of HPV E6 genes were estimated by PAML 4.8 server. The secondary and tertiary structure of E6 protein were predicted by PSIPred and Swiss-model. The T-cell antigen epitopes of E6 protein were predicted by IEDB. RESULTS: α-9 HPV has a high prevalence in Sichuan, China. From 2012 to 2017, 18,067 cell cervical samples were collected, and 3135 were detected with α-9 HPV infection. Among which, 250 cases HPV-16 E6, 96 cases HPV-31 E6, 216 cases HPV-33 E6, 288 cases HPV-52 E6 and 405 cases HPV-58 E6 were successfully amplified, 17, 6, 6, 13, and 4 non-synonymous nucleotide mutations were respectively detected in HPV-16, 31, 33, 52, and 58 E6, 7 positive selection sites of α-9 HPV E6 were selected out (D32E of HPV-16 E6, K35N, K93N and R145I of HPV-33 E6, K93R of HPV-52 E6, K93N and R145K of HPV-58 E6). The structure and antigen epitopes of E6 protein with amino acid substitution differ from those of wild-type E6 protein, especially for the mutation located in the E6 positive selection site. CONCLUSIONS: HPV E6 nucleotide non-synonymous mutation in the positive selection site influence the protein structure and decrease the antigen epitopes affinity of the E6 protein overall, making it more difficult for the HPV-infected cells to be detected by the immune system, and enhancing the HPV adaptability to the environment. Mutations influence the validity of HPV clinical diagnostic probes, the polymorphism analysis of α-9 HPV E6 enrich the data of HR-risk HPV in Sichuan China, and the detection probes designed with the polymorphism data in mind can improve the efficiency of clinical detection; Mutations influence epitopes affinity, the association of E6 polymorphism and epitope affinity can improve the design of therapeutic vaccine with good immunity and high generality antigen epitope; The above study all provide a good theoretical basis for the prevention and treatment of HPV-related diseases.
Subject(s)
Alphapapillomavirus , Oncogene Proteins, Viral , Repressor Proteins , Alphapapillomavirus/genetics , China/epidemiology , Epitopes, T-Lymphocyte/genetics , Female , Human papillomavirus 16 , Humans , Oncogene Proteins, Viral/chemistry , Oncogene Proteins, Viral/genetics , Papillomavirus Infections , Phylogeny , Polymorphism, Single Nucleotide , Repressor Proteins/chemistry , Repressor Proteins/genetics , Uterine Cervical NeoplasmsABSTRACT
Understanding the chemical composition and molecular transformation in soil dissolved organic matter (DOM) is important to the global carbon cycle. To address this issue, ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was applied to investigate DOM molecules in 36 paddy soils collected from subtropical China. All the detected 7576 unique molecules were divided into seven compound groups, and nine trade-off relationships between different compound groups were revealed based on principal component analysis and Pearson's correlation. An optimized method was developed to evaluate all potential molecular transformations in DOM samples. The concept of thermodynamics was introduced to evaluate the identified molecular transformations and classify them as thermodynamically favorable (TFP) and thermodynamically limited (TLP) processes. Here, we first tried to understand the molecular trade-offs by using the potential molecular transformations. All the nine trade-offs could be explained by molecular transformations. Six trade-offs had bases of biochemical reactions, and the trade-off-related direct transformations could explain the content variations of carbohydrate-like, condensed aromatic-like, tannin-like, and lignin-like compounds in TLP. More reasonable explanations existed in the TLP rather than TFP, which demonstrated the critical role of external energy in the molecular transformation of soil DOM.
Subject(s)
Dissolved Organic Matter , Soil , Carbon Cycle , China , Mass Spectrometry , Soil/chemistryABSTRACT
Atrial fibrillation (AF), the commonest arrhythmia, shows associations with various disease conditions. Mounting evidence indicates that atrial fibrosis is an important part of the arrhythmogenic substrate, with an essential function in the generation of conduction abnormalities that underlie the transition from paroxysmal to persistent AF, which in turn contributes to AF perpetuation. Left atrial (LA) fibrosis is considered a possible major factor and predictor in AF treatment. The present review provides insights into LA fibrosis' association with AF. The information is focused on clinical aspects and mechanisms, clinical evaluating methods that evaluate fibrosis changes and examining possible options for the prevention of atrial fibrosis.
Subject(s)
Atrial Fibrillation/pathology , Heart Atria/pathology , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Biomarkers , Disease Susceptibility , Echocardiography , Electrocardiography , Fibroblasts/metabolism , Fibrosis , Humans , Magnetic Resonance Imaging , Myofibroblasts/metabolism , RecurrenceABSTRACT
We report herein the (R)-3,3'-Br2-BINOL-catalyzed enantioselective conjugate addition of organic boronic acids to ß,γ-unsaturated α-ketoesters to generate the corresponding Michael addition products in moderate to high yields and with moderate to excellent enantioselectivities (up to 99% ee). This catalytic system features characteristics of mild reaction conditions, high efficiency, and tolerance to alkenylboronic acids and heteroarylboronic acids.
Subject(s)
Boronic Acids , Esters , Catalysis , StereoisomerismABSTRACT
A highly electronegative carboxyl-decorated anionic metal-organic framework (MOF), (Me2NH2)2[In2(THBA)2](CH3CN)9(H2O)21 (InOF; H4THBA = [1,1':4',1â³-terphenyl]-2',3,3â³,5,5',5â³-hexacarboxylic acid), with high-density electronegative functional sites was designed and constructed. One unit cell of InOF possesses 12 negative sites that originate from the negatively charged secondary building unit [In(COO)4]- and exposed carboxyl groups on the ligand. The abundant electronegative sites can facilitate the hopping of ions in channels and thus result in highly efficient ion conductivities for various metal ions. Our results show that Li+-loaded materials have a remarkably high ion conductivity of 1.49 × 10-3 S/cm, an ion transference number of 0.78, and a relatively low activation energy of 0.19 eV. The Na+, K+, and Zn2+ ion conductivities of InOF are 7.97 × 10-4, 7.69 × 10-4, and 1.22 × 10-3 S/cm at 25 °C, respectively.
ABSTRACT
Tongguan capsule is a compound Chinese medicine used to treat ischaemic heart diseases. This study aimed to investigate whether Tongguan capsule-derived herb (TGD) has a preventive effect on atrial fibrillation (AF) in post-myocardial infarction (MI) rats and to determine the underlying mechanisms. MI was induced by ligation of the left anterior descending coronary artery. TGD was administered to the post-MI rats over a 4-week period. The TGD-treated rats had lower rates of AF inducibility and shorter AF durations than the MI rats. TGD improved the left atrial (LA) conduction velocity and homogeneity. It reduced the fibrosis-positive areas and the protein levels of collagen types I and III in the left atrium. In vitro, it inhibited the expression of collagen types I and III by inhibiting the proliferation, migration, differentiation and cytokine secretion of cardiac fibroblasts (CFs). In conclusion, the current study demonstrated that TGD reduces susceptibility to AF and improves LA conduction function in rats with post-MI by inhibiting left atrial fibrosis and modulating CFs. Targeting the CF population may be a novel antiarrhythmic therapeutic approach.
Subject(s)
Anti-Arrhythmia Agents/administration & dosage , Atrial Fibrillation/prevention & control , Capsules/administration & dosage , Drugs, Chinese Herbal/chemistry , Fibroblasts/drug effects , Fibrosis/drug therapy , Heart Atria/drug effects , Animals , Apoptosis , Atrial Fibrillation/pathology , Cell Cycle , Cell Movement , Cell Proliferation , Cells, Cultured , Fibroblasts/cytology , Fibrosis/pathology , Heart Atria/pathology , Heart Rate , Male , Rats , Rats, Sprague-DawleyABSTRACT
Danqi soft capsule (DQ) is a traditional Chinese medicine containing Salvia miltiorrhiza and Panax notoginseng; it is safe and efficient in treating ischaemic heart diseases. The purpose of the present study was to assess whether DQ could prevent infarct border zone (IBZ) remodelling and decrease ventricular arrhythmias occurrence in post-myocardial infarction (MI) stage. MI was induced by a ligation of the left anterior descending coronary artery. DQ was administered to the post-MI rats started from 1 week after MI surgery for 4 weeks. The results showed that DQ treatment significantly attenuated tachyarrhythmia induction rates and arrhythmia score in post-MI rats. In echocardiography, DQ improved left ventricular (LV) systolic and diastolic function. Histological assessment revealed that DQ significantly reduced fibrotic areas and myocyte areas, and increased connexin (Cx) 43 positive areas in IBZ. Western blot revealed that DQ treatment significantly reduced the protein expression levels of type I and III collagens, α-smooth muscle actin (α-SMA), transforming growth factor-ß1 (TGF-ß1) and Smad3 phosphorylation, while increasing Cx43 amounts. Overall, these findings mainly indicated that DQ intervention regulates interstitial fibrosis, Cx43 expression and myocyte hypertrophy by TGF-ß1/Smad3 pathway in IBZ, inhibits LV remodelling and reduces vulnerability to tachyarrhythmias after MI. This study presents a proof of concept for novel antiarrhythmic strategies in preventing IBZ remodelling, modifying the healed arrhythmogenic substrate and thus reducing susceptibility to ventricular arrhythmias in the late post-MI period.
Subject(s)
Arrhythmias, Cardiac/drug therapy , Capsules/pharmacology , Drugs, Chinese Herbal/pharmacology , Heart Ventricles/drug effects , Myocardial Infarction/drug therapy , Ventricular Remodeling/drug effects , Animals , Arrhythmias, Cardiac/metabolism , Diastole/drug effects , Echocardiography/methods , Fibrosis/drug therapy , Fibrosis/metabolism , Heart Ventricles/metabolism , Male , Myocardial Infarction/metabolism , Myocardial Ischemia/drug therapy , Myocardial Ischemia/metabolism , Myocardium/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects , Smad3 Protein/metabolism , Systole/drug effects , Transforming Growth Factor beta1/metabolismABSTRACT
Temperate forests cover 16% of the global forest area. Within these forests, the understorey is an important biodiversity reservoir that can influence ecosystem processes and functions in multiple ways. However, we still lack a thorough understanding of the relative importance of the understorey for temperate forest functioning. As a result, understoreys are often ignored during assessments of forest functioning and changes thereof under global change. We here compiled studies that quantify the relative importance of the understorey for temperate forest functioning, focussing on litter production, nutrient cycling, evapotranspiration, tree regeneration, pollination and pathogen dynamics. We describe the mechanisms driving understorey functioning and develop a conceptual framework synthesizing possible effects of multiple global change drivers on understorey-mediated forest ecosystem functioning. Our review illustrates that the understorey's contribution to temperate forest functioning is significant but varies depending on the ecosystem function and the environmental context, and more importantly, the characteristics of the overstorey. To predict changes in understorey functioning and its relative importance for temperate forest functioning under global change, we argue that a simultaneous investigation of both overstorey and understorey functional responses to global change will be crucial. Our review shows that such studies are still very scarce, only available for a limited set of ecosystem functions and limited to quantification, providing little data to forecast functional responses to global change.
Subject(s)
Ecosystem , Forests , Biodiversity , TreesABSTRACT
This study aimed to investigate whether matrine could prevent atrial fibrillation (AF) after myocardial infarction by reducing left atrial fibrosis, and to determine the underlying mechanisms in isolated cardiac fibroblasts (CFs). Five weeks after MI, matrine-treated rats had lower rates of AF inducibility and shorter AF duration than MI rats. Matrine improved the left atrial conduction velocity and homogeneity. Matrine decreased the fibrosis positive areas and the protein levels of type I collagen and type III collagen in the left atrium. Matrine inhibited CFs differentiation to myofibroblasts and the expression of transforming growth factor-beta 1 and matrix metalloproteinase 9. In vitro, matrine inhibited the CFs proliferation, migration, differentiation, and secretion ability. These in vitro and in vivo data demonstrated that matrine has the potential to reduce susceptibility to AF after MI due, at least in part, to reduced atrial fibrosis via inhibiting CFs proliferation, migration, differentiation, and secretion ability.
Subject(s)
Alkaloids/pharmacology , Anti-Arrhythmia Agents/pharmacology , Atrial Fibrillation/prevention & control , Atrial Function, Left/drug effects , Atrial Remodeling/drug effects , Heart Atria/drug effects , Heart Rate/drug effects , Myocardial Infarction/drug therapy , Quinolizines/pharmacology , Action Potentials/drug effects , Animals , Atrial Fibrillation/etiology , Atrial Fibrillation/metabolism , Atrial Fibrillation/physiopathology , Cell Differentiation/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Collagen Type I/metabolism , Collagen Type III/metabolism , Disease Models, Animal , Fibroblasts/drug effects , Fibroblasts/metabolism , Fibroblasts/pathology , Fibrosis , Heart Atria/metabolism , Heart Atria/pathology , Heart Atria/physiopathology , Male , Myocardial Infarction/complications , Myocardial Infarction/physiopathology , Rats, Sprague-Dawley , MatrinesABSTRACT
As the largest research-oriented specialty department in national traditional Chinese medicine hospitals, the Department of Critical Care Medicine in Guangdong Provincial Hospital of Chinese Medicine insists on the development mode combined with clinical medicine and scientific research. By taking clinical and basic researches for integrative medicine preventing and treating acute myocardial in-farction and sepsis as a breakthrough, authors explored key problems of Chinese medicine in improving the prognosis related diseases and patients' quality of life. In recent 3 years our department has successively become the principal unit of the national key specialties cooperative group of critical care medicine (awarded by State Administration of Traditional Chinese Medicine), the key clinical specialties (awarded by National Health and Family Planning Commission), and Guangzhou key laboratory construction unit, and achieved overall lap in clinical medical treatment, personnel training, scientific research, and social service.
Subject(s)
Biomedical Research , Clinical Medicine , Hospital Departments/organization & administration , Integrative Medicine , China , Critical Care , Humans , Medicine, Chinese Traditional , Quality of LifeABSTRACT
Hypoxic-ischemic brain damage (HIBD) is referred to a common type of cerebral damage, which is caused by injury, leading to shallow bleeding in the cortex with intact cerebral pia mater. In recent years, studies show that a various kinds of immune cells and immune cellular factors are involved in the occurrence of HIBD. CC chemokine receptor 2 (CCR2) is a representative of CC chemokine receptor, and is widely distributed in cerebral neuron, astrocyte, and microglial cells, and is the main chemo-tactic factor receptor in brain tissue. CC chemokine ligand 2 (CCL2) is a kind of basophilic protein and the ligand of CCR2, and plays an important role in inflammation. In order to provide evidence for correlational studies in HIBD, this review will introduce the biological characteristics of CCR2 and CCL2, and illustrate the relationship between the immunoreactivity and HIBD.
Subject(s)
Brain Injuries/metabolism , Chemokine CCL2/metabolism , Hypoxia-Ischemia, Brain/metabolism , Animals , Brain Injuries/drug therapy , Brain Injuries/pathology , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Chemokine CCL2/genetics , Chemokines, CC/metabolism , Macrophage Inflammatory Proteins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, CCR2/antagonists & inhibitors , Receptors, CCR2/genetics , Receptors, CCR2/metabolismABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a member of cyclin-dependent kinase family, which does not directly regulate cell cycle. Through phosphorylation of target protein, CDK5 plays an irreplaceable role in the development, reparation and degeneration of neurons. Brain injury refers to the organic injury of brain tissue caused by external force hit on the head. Owing to the stress and repair system activated by our body itself after injury, various proteins and enzymes of the brain tissues are changed quantitatively, which can be used as indicators for estimating the time of injury. This review summarizes the progress on the distribution, the activity mechanism and the physiological effects of CDK5 after brain injury and its corresponding potential served as a marker for brain injury determination.
Subject(s)
Brain Injuries/drug therapy , Brain/drug effects , Cyclin-Dependent Kinase 5/antagonists & inhibitors , Neuroprotective Agents/pharmacology , Brain/pathology , Brain/physiopathology , Brain Injuries/pathology , Brain Injuries/physiopathology , Cyclin-Dependent Kinase 5/metabolism , Nerve Tissue Proteins/metabolism , Neurons , Phosphorylation/drug effects , Time FactorsABSTRACT
BACKGROUND: Lung ultrasound (LUS) can diagnose extravacular lung water (EVLW) through the visualization of B lines in both humans and large animals. However, there are no published data on the use of ultrasound to detect EVLW in rats, the gold standard to evaluate of EVLW in rats is post-mortem gravimetric analysis. The present study was designed to determine the similarity between lung sonography and gravimetric measurements of EVLW in rats in an acute lung injury (ALI) model. METHODS: Thirty male Sprague-Dawley rats were randomized into control and experimental groups. The B lines were measured byLUS at baseline. ALI was induced by the intravenous administration of oleic acid (OA) at a dose of 9 ul/100 mg, and controls were injected the same amount of isotonic saline. After 1 h, B-lines were measured by LUS in each rat following the induction of ALI. At the end of each experiment, both lungs were dissected, weighed and dried to determine wet/dry weight ratio according to the standard gravimetric methodology. Lung samples from three rats in each group were examined histologically. RESULTS: B-lines were present in all rats from experimental group at 1 h point after OA injection. The statistical correlation between the two methods of assessing EVLW provided an r = 0.834 (p < 0.001). Repeatability studies of the LUS technique (Bland-Altman plots) showed good intra-observer and inter-observer reproducibility. CONCLUSION: The data suggest that, in an experimental rat model of ALI, B lines score as assessed by LUS can provide an easy, semi-quantitative, noninvasive. Real-time index of EVLW which is strongly correlated to experimental gravimetric assessments.
Subject(s)
Acute Lung Injury/diagnostic imaging , Extravascular Lung Water/diagnostic imaging , Lung/diagnostic imaging , Acute Lung Injury/physiopathology , Animals , Disease Models, Animal , Male , Oleic Acid/administration & dosage , Rats , Rats, Sprague-Dawley , Reproducibility of Results , Sodium Chloride/administration & dosage , UltrasonographyABSTRACT
The two herbs Ligusticum chuanxiong (LC) Hort. (Umbelliferae) and Gastrodia elata (GE) Blume (Orchidaceae), are widely used in the clinic for the treatment of migraine. This article aims to understand the effects of LC and GE on blood-brain barrier (BBB) permeability in migraine rats. Serotonin, excitatory amino acids (EAAs) and matrix metalloproteinase-9 (MMP-9) were determined at different sampling times to assess BBB disruption during a migraine attack. BBB permeability was examined by fluorescence imaging and Evans blue dye (EBD) extravasation. The results showed that the expression of serotonin in migraine rat brain was enhanced from 30 min to 120 min and glutamate (Glu) was suppressed from 30 min to 60 min in LC-GE group compared with the model group (p < 0.05 or 0.01), while the MMP-9 levels in migraine rat blood was increased at 30 min as well as decreased at 120 min in LC-GE group compared with the model group (p < 0.05 or 0.01). EBD levels in rat brain were significantly lower at 30-60 min and 120-150 min in LC-GE group than that of the model group (p < 0.05 or 0.01). Our findings demonstrated that LC and GE might decrease BBB permeability and maintain its integrity through regulating serotonin, EAAs and MMP-9 in migraine rats.
Subject(s)
Blood-Brain Barrier/drug effects , Gastrodia/chemistry , Ligusticum/chemistry , Migraine Disorders/metabolism , Plant Extracts/pharmacology , Animals , Brain Chemistry/drug effects , Excitatory Amino Acids/metabolism , Male , Matrix Metalloproteinase 9/metabolism , Rats , Rats, Sprague-Dawley , Serotonin/metabolismABSTRACT
Frequent oceanic oil spill incidents and the discharge of industrial oily wastewaters have caused serious threats to environments, food chains and human beings. Lignin wastes with many reactive groups exist as the byproducts from bioethanol and pulping processing industries, and they are either discarded as wastes or directly consumed as a fuel. To make full use of lignin wastes and simultaneously deal with oily wastewaters, porous lignin-based composites have been rationally designed and prepared. In this review, recent advances in the preparation of porous lignin-based composites are summarized in terms of aerogels, sponges, foams, papers, and membranes, respectively. Then, the mechanisms and the application of porous lignin-based adsorbents and filtration materials for oil/water separation are discussed. Finally, the challenges and perspectives of porous lignin-based composites are proposed in the field of oil/water separation. The utilization of abundant lignin wastes can replace fossil resources, and meanwhile porous lignin-based composites can be used to efficiently treat with oily wastewaters. The above utilization strategy opens an avenue to the rational design and preparation of lignin wastes with high-added value, and gives a possible solution to use lignin wastes in a sustainable and environmentally friendly way.
Subject(s)
Body Fluids , Lignin , Humans , Porosity , Wastewater , FiltrationABSTRACT
In vivo mechanical characterization of skin finds broad applications in understanding skin aging, diagnosis of some skin diseases and assessing the effectiveness of diverse skin care strategies. Skin has a layered structure consisting of the epidermis, dermis and subcutaneous layers. Although much effort has been made towards mechanical characterization of skin, it remains a challenging issue to measure the mechanical properties of an individual layer in vivo. To address this issue, we here report a guided wave elastography method for layered human skin which incorporates the effect of muscle states. Both finite element simulations and phantom experiments have been performed to validate the method. For skin-mimicking phantoms with different fat layer thicknesses, the errors in the identified shear modulus of the skin layers are no more than 11 %. In vivo experiments have been carried out on 6 healthy subjects to demonstrate the potential use of the method in clinics. A statistical analysis indicates the muscle contraction contributes to the stiffening of the skin (p < 0.001). Finally, a phase diagram has been constructed to reveal the extent to which muscle sates (including both passive and active states) affect the measurement of elastic modulus of a skin layer, which may guide the application of the method in practice.
ABSTRACT
Air humidity is an important environmental factor restricting the fruit body growth of Auricularia heimuer. Low air humidity causes the fruit body to desiccate and enter dormancy. However, the survival mechanisms to low air humidity for fruit bodies before dormancy remain poorly understood. In the present study, we cultivated A. heimuer in a greenhouse and collected the fruit bodies at different air humidities (90%, 80%, 70%, 60%, and 50%) to determine the contents of malondialdehyde (MDA) and non-enzymatic antioxidants such as ascorbic acid (AsA) and glutathione (GSH); and the activities of enzymatic antioxidants including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX) and glutathione reductase (GR). Results showed that the MDA contents tended to increase with decreasing relative air humidity. Relative air humidity below 90% caused membrane lipid peroxidation and oxidative stress (based on MDA contents) to the fruit body, which we named air humidity stress. In contrast to the control and with the degree of stress, the GSH contents and activities of SOD, CAT, GR, GPX, and APX tended to ascend, whereas AsA showed a declining trend; the POD activity only rose at 50%. The antioxidants favored the fruit body to alleviate oxidative damage and strengthened its tolerance to air humidity stress. The antioxidant defense system could be an important mechanism for the fruit body of A. heimuer in air humidity stress.