ABSTRACT
Powdery mildew is an apple disease caused by the obligate trophic fungus Podosphaera leucotricha. Basic helix-loop-helix (bHLH) transcription factors play important roles in plant development and stress responses, and they have been widely studied in model plants such as Arabidopsis thaliana. However, their role in the stress response of perennial fruit trees remains unclear. Here, we investigated the role of MdbHLH093 in the powdery mildew of apples. The expression of MdbHLH093 was significantly induced during the infection of apples with powdery mildew, and the allogenic overexpression of MdbHLH093 in A. thaliana enhanced the resistance to powdery mildew by increasing the accumulation of hydrogen peroxide (H2O2) and activating the salicylic acid (SA) signaling pathway. The transient overexpression of MdbHLH093 in apple leaves increased the resistance to powdery mildew. Conversely, when MdbHLH093 expression was silenced, the sensitivity of apple leaves to powdery mildew was increased. The physical interaction between MdbHLH093 and MdMYB116 was demonstrated by yeast two-hybrid, bi-molecular fluorescence complementation, and split luciferase experiments. Collectively, these results indicate that MdbHLH093 interacts with MdMYB116 to improve apple resistance to powdery mildew by increasing the accumulation of H2O2 and activating the SA signaling pathway, as well as by providing a new candidate gene for resistance molecular breeding.
Subject(s)
Arabidopsis , Transcription Factors , Transcription Factors/genetics , Transcription Factors/metabolism , Hydrogen Peroxide/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Salicylic Acid , Erysiphe , Arabidopsis/genetics , Signal Transduction , Gene Expression Regulation, Plant , Plant Diseases/genetics , Plant Diseases/microbiology , Disease Resistance/geneticsABSTRACT
Phospholipases can disrupt host membranes and are important virulence factors in many pathogens. VvPlpA is a phospholipase A2 secreted by Vibrio vulnificus and essential for virulence. Its homologs, termed thermolabile hemolysins (TLHs), are widely distributed in Vibrio bacteria, but no structural information for this virulence factor class is available. Herein, we report the crystal structure of VvPlpA to 1.4-Å resolution, revealing that VvPlpA contains an N-terminal domain of unknown function and a C-terminal phospholipase domain and that these two domains are packed closely together. The phospholipase domain adopts a typical SGNH hydrolase fold, containing the four conserved catalytic residues Ser, Gly, Asn, and His. Interestingly, the structure also disclosed that the phospholipase domain accommodates a chloride ion near the catalytic His residue. The chloride is five-coordinated in a distorted bipyramid geometry, accepting hydrogen bonds from a water molecule and the amino groups of surrounding residues. This chloride substitutes for the most common Asp/Glu residue and forms an unusual Ser-His-chloride catalytic triad in VvPlpA. The chloride may orient the catalytic His and stabilize the charge on its imidazole ring during catalysis. Indeed, VvPlpA activity depended on chloride concentration, confirming the important role of chloride in catalysis. The VvPlpA structure also revealed a large hydrophobic substrate-binding pocket that is capable of accommodating a long-chain acyl group. Our results provide the first structure of the TLH family and uncover an unusual Ser-His-chloride catalytic triad, expanding our knowledge on the biological role of chloride.
Subject(s)
Catalytic Domain , Chlorides/chemistry , Histidine/chemistry , Phospholipases A2/chemistry , Serine/chemistry , Vibrio vulnificus/enzymology , Amino Acid Sequence , Protein Conformation , Sequence AlignmentABSTRACT
Liquidliquid phase separation was observed in aqueous MgSO4 solutions with excess H2SO4 at elevated temperatures; the aqueous MgSO4/H2SO4 solutions separated into MgSO4-rich droplets (fluid F1) and a MgSO4-poor phase (fluid F2) during heating. The phase separation temperature increases with SO4(2)/Mg2+ ratio at a constant MgSO4 concentration. At a MgSO4/H2SO4 ratio of 5, the liquidliquid phase separation temperature decreases with an increase in MgSO4 concentration up to â¼1.0 mol/kg and then increases at higher concentrations, showing a typical macroscale property of polymer solutions with a lower critical solution temperature (LCST) of â¼271.4 °C. In situ Raman spectroscopic analyses show that the MgSO4 concentration in fluid F1 increases with an increase in temperature, whereas that in fluid F2 decreases with an increase in temperature. In addition, HSO4(), which does not readily form complexes with Mg(2+), tends to accumulate in fluid F2. Analyses of the v1(SO4(2)) bands confirmed the presence of four-sulfate species of unassociated SO4(2) (â¼980 cm(1)), contact ion pairs (CIPs; â¼995 cm(1)), and triple ion pairs (TIPs; â¼1005 cm(1)) in aqueous solution, and more complex ion pair chain structure (â¼1020 cm(1)) in fluid F1. Comparison of the sulfate species in fluids F1 and F2 at 280 °C suggests that SO4(2) in fluid F2 is less associated with Mg(2+). On the basis of in situ visual and Raman spectroscopic observations, we suggest that the formation of the complex Mg(2+)SO4(2) ion association might be responsible for the liquidliquid phase separation. In addition, Raman spectroscopic analyses of the OH stretching bands indicate that the hydrogen bonding in fluid F1 is stronger than that in fluid F2, which might be ascribed to the increasing probability of collision of H2O with Mg(2+) and SO4(2) in fluid F1.
Subject(s)
Magnesium Sulfate/chemistry , Spectrum Analysis, Raman , Temperature , Hydrogen Bonding , Liquid-Liquid Extraction , Magnesium Sulfate/isolation & purificationABSTRACT
The synchronous fluorescence spectroscopy and two dimensional correlation analysis method were applied to study the aggregation behavior of acid-soluble collagen solutions (0.2, 0.4 and 1.6 mg x mL(-1)) during the heating process of 10-70 degrees C. It was found that the fluorescence excited at 292 and 282 nm (delta lamda=9 nm) belongs to the tyrosine (Tyr) residues which participate in forming hydrogen bonds or not, respectively. The two dimensional correlation analysis with the temperature varying showed that with the temperature increased (10-30 degrees C) hydrogen bonds among collagen molecular with Tyr residues formed in the 0.2 mg x mL(-1) collagen solution, while the higher aggregations of collagen molecular and hydrophobic micro-domains appeared in the 0.4 and 1.6 mg x mL(-1) collagen solutions. With approaching the denatured temperature of collagen (36-38 degrees C), the hydrophobic micro-domain and aggregates seemed to be broken in the 0.4 and 1.6 mg x mL(-1) collagen solutions, however the hydrogen bonds in the 0.2 mg x mL(-1) were stable. Above the denaturation temperature of collagen, the triple-helix structure of collagen molecular in solution of each concentration tended to be loose. In the heating process of 45-70 degrees C, this trend was more obvious.
Subject(s)
Collagen/chemistry , Temperature , Fluorescence , Spectrometry, Fluorescence , TyrosineABSTRACT
Carbonaceous fluid within mineral-hosted inclusions provides important information for carbon cycle in deep Earth. In addition to CH4 and CO2, heavy hydrocarbons (e.g., C2H6 and C3H8) are frequently observed in carbonaceous fluid inclusions (i.e, wet gas inclusions with C1/∑Ci < 0.95). However, determination of the composition of such complex volatiles is difficult based on traditional microthermometric measurements. Here we carried out experimental calibrations on Raman spectroscopic measurements of the pressure (P) and composition of the CH4 ± C2H6 ± C3H8 ± H2S system at room temperature and 0.1-130 MPa. We confirmed that the C-H symmetric stretching vibration band of CH4 [ν1(CH4), â¼2917 cm-1] shifted to lower wavenumber with rising pressure, thus the P-ν1(CH4) relationship could be applied to calculate the pressure of wet gas. It should be noted that the presence of C2+ and/or H2S will shift the [ν1(CH4)] to lower wavenumber at constant pressure (with the order of C3H8 ≥ H2S > C2H6). Obviously, the P-ν1(CH4) relationship derived from pure CH4 system could not be simply applied to wet gas inclusion, otherwise the pressure would be overestimated. To avoid the overlap of the C-H vibrations of CH4, C2H6 and C3H8, the peak areas and peak heights of the overtone vibration of CH4 [2ν4(CH4), â¼2580 cm-1], C-C symmetric stretching vibrations of C2H6 [ν3(C2H6), â¼995 cm-1] and C3H8 [ν8(C3H8), â¼868 cm-1], and S-H symmetric stretching vibration of H2S [ν1(H2S), â¼2612 cm-1] were fitted using Gaussian + Lorentz functions. The obtained peak areas and peak heights were then used to calculate the Raman quantification factors (F factor and G factor, respectively) of C2H6, C3H8 and H2S relative to CH4, respectively. Both the F factor and G factor increased with rising pressure, whereas the FC2H6, FC3H8 and GH2S kept nearly constant at â¼5.69, 6.39 and 153.8, respectively in high pressure gas mixtures (e.g., >30 MPa). Therefore, for inclusions with higher internal pressure, the molar ratio of CH4, C2H6, C3H8 and H2S could be determined by the aforementioned F and G factors. This method was applied to the calcite-hosted single-phase gas inclusions in the Upper Permian Changxing Formation carbonate reservoir from the eastern Sichuan Basin (South China). Our results indicated that the trapping pressure would be obviously overestimated if the presence of heavy hydrocarbons was not taken into account.
ABSTRACT
Vascular injury is central to the pathogenesis and progression of cardiovascular diseases, however, fostering alternative strategies to alleviate vascular injury remains a persisting challenge. Given the central role of cell-derived nitric oxide (NO) in modulating the endogenous repair of vascular injury, NO-generating proteolipid nanovesicles (PLV-NO) are designed that recapitulate the cell-mimicking functions for vascular repair and replacement. Specifically, the proteolipid nanovesicles (PLV) are versatilely fabricated using membrane proteins derived from different types of cells, followed by the incorporation of NO-generating nanozymes capable of catalyzing endogenous donors to produce NO. Taking two vascular injury models, two types of PLV-NO are tailored to meet the individual requirements of targeted diseases using platelet membrane proteins and endothelial membrane proteins, respectively. The platelet-based PLV-NO (pPLV-NO) demonstrates its efficacy in targeted repair of a vascular endothelium injury model through systemic delivery. On the other hand, the endothelial cell (EC)-based PLV-NO (ePLV-NO) exhibits suppression of thrombosis when modified onto a locally transplanted small-diameter vascular graft (SDVG). The versatile design of PLV-NO may enable a promising therapeutic option for various vascular injury-evoked cardiovascular diseases.
Subject(s)
Nitric Oxide , Proteolipids , Vascular System Injuries , Nitric Oxide/metabolism , Animals , Vascular System Injuries/metabolism , Proteolipids/metabolism , Disease Models, Animal , Mice , Humans , Nanoparticles/chemistry , MaleABSTRACT
BACKGROUND: Associating liver partition with portal vein ligation for staged liver resection (ALPPS) has been used in the treatment of patients with advanced or massive liver cancer without sufficient future liver remnant, but concerns remain regarding tumor outcomes and surgical safety. This study aims to evaluate the efficacy and safety of a new procedure, Hepatic artery restriction operation combined with ALPPS (HARO-ALPPS), in the treatment of HCC patients especially with severe fibrosis. METHODS: This retrospective study analyzed 8 patients who underwent HARO-ALPPS for HCC and compared their outcomes with 64 patients who underwent conventional ALPPS. The primary outcomes assessed were liver regeneration ability (measured by relative and absolute kinetic growth rates), postoperative complications, and mortality. The secondary outcomes included overall survival and disease-free survival. RESULTS: HARO-ALPPS significantly restricted the blood supply of the hepatic artery. One week after surgery, the blood flow of the right hepatic artery dropped to 62.1%. At the same time, HARO-ALPPS shows superior liver regeneration ability, which is particularly prominent in the background of liver fibrosis. No serious complications occurred after HARO-ALPPS. The overall survival rate of HARO-ALPPS was 75%, which was higher than that of ALPPS (64%, P=0.816). CONCLUSION: Compared to conventional ALPPS, HARO-ALPPS exhibits a better liver regeneration ability, and favorable long-term outcomes. Further prospective studies are needed to validate these findings and evaluate the long-term oncologic outcomes of this novel procedure.
ABSTRACT
Degradability is vital for bone filling and plays an important role in bone regeneration. Evidence indicates that apatite-based calcium phosphate cement (ACPC) is a prospective biomaterial for bone repair with enhanced osteogenesis. However, poor degradability restricts their clinical application. In this study, MgZnCa-doped ACPC (MgZnCa/ACPC) composites were fabricated by adding 3 (wt) % amorphous MgZnCa powder in the solid phase of ACPC to enhance the biodegradation and bioactivity of the apatite ACPC. The chemical and the physical properties of the MgZnCa/ACPC composite were investigated and compared with the ACPC composite. The results showed that the incorporation of MgZnCa improved both the degradability and the compressive strength of the ACPC composite. X-ray diffraction and Fourier transform infrared spectrometry analysis suggested significant changes in the microstructures of the composites due to the incorporation and the anodic dissolution of MgZnCa alloy. These findings indicate that the MgZnCa/ACPC composite is capable of facilitating bone repair and regeneration by endowing favorable degradation property.
Subject(s)
Alloys , Apatites , Apatites/metabolism , Alloys/chemistry , Prospective Studies , Materials Testing , Calcium Phosphates/chemistry , Bone Cements/chemistryABSTRACT
IMPORTANCE: Cold seeps occur in continental margins worldwide and are deep-sea oases. Anaerobic oxidation of methane is an important microbial process in the cold seeps and plays an important role in regulating methane content. This study elucidates the diversity and potential activities of major microbial groups in dependent anaerobic methane oxidation and sulfate-dependent anaerobic methane oxidation processes and provides direct evidence for the occurrence of nitrate-/nitrite-dependent anaerobic methane oxidation (Nr-/N-DAMO) as a previously overlooked microbial methane sink in the hydrate-bearing sediments of the South China Sea. This study provides direct evidence for occurrence of Nr-/N-DAMO as an important methane sink in the deep-sea cold seeps.
Subject(s)
Geologic Sediments , Methane , Anaerobiosis , Methane/metabolism , RNA, Ribosomal, 16S , Oxidation-Reduction , Nitrates , ChinaABSTRACT
Flexible thermoelectric materials have attracted increasing interest because of their potential use in thermal energy harvesting and high-spatial-resolution thermal management. However, a high-performance flexible micro-thermoelectric device (TED) compatible with the microelectronics fabrication process has not yet been developed. Here a universal epitaxial growth strategy is reported guided by 1D van der Waals-coupling, to fabricate freestanding and flexible hybrids comprised of single-wall carbon nanotubes and ordered (Bi,Sb)2 Te3 nanocrystals. High power factors ranging from ≈1680 to ≈1020 µW m-1 K-2 in the temperature range of 300-480 K, combined with a low thermal conductivity yield a high average figure of merit of ≈0.81. The fabricated flexible micro-TED module consisting of two p-n couples of freestanding thermoelectric hybrids has an unprecedented open circuit voltage of ≈22.7 mV and a power density of ≈0.36 W cm-2 under ≈30 K temperature difference, and a net cooling temperature of ≈22.4 K and a heat absorption density of ≈92.5 W cm-2 .
ABSTRACT
Vascular regeneration and patency maintenance, without anticoagulant administration, represent key developmental trends to enhance small-diameter vascular grafts (SDVG) performance. In vivo engineered autologous biotubes have emerged as SDVG candidates with pro-regenerative properties. However, mechanical failure coupled with thrombus formation hinder translational prospects of biotubes as SDVGs. Previously fabricated poly(ε-caprolactone) skeleton-reinforced biotubes (PBs) circumvented mechanical issues and achieved vascular regeneration, but orally administered anticoagulants were required. Here, highly efficient and biocompatible functional modifications were introduced to living cells on PB lumens. The 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-methoxy (DMPE)-PEG-conjugated anti-coagulant bivalirudin (DPB) and DMPE-PEG-conjugated endothelial progenitor cell (EPC)-binding TPS-peptide (DPT) modifications possessed functionality conducive to promoting vascular graft patency. Co-modification of DPB and DPT swiftly attained luminal saturation without influencing cell viability. DPB repellent of non-specific proteins, DPB inhibition of thrombus formation, and DPB protection against functional masking of DPT's EPC-capture by blood components, which promoted patency and rapid endothelialization in rat and canine artery implantation models without anticoagulant administration. This strategy offers a safe, facile, and fast technical approach to convey additional functionalization to living cells within tissue-engineered constructs.
ABSTRACT
This study aimed to identify the effectiveness of platelet-rich plasma (PRP) for patients operated with anterior cruciate ligament reconstruction (ACLR). Databases of PubMed, Embase, and CENTRAL were independently retrieved by two authors, for identifying the eligible randomized controlled trials (RCTs) comparing the clinical and imaging outcomes of ACL reconstructed patients augmented with or without PRP. The Cochrane Collaboration tool was utilized to assess the risk of bias of the included trials. We qualitatively synthesized the outcomes include the image evaluations on the healing of bone tunnels, graft remodeling, donor site healing and tunnel widening, and clinical evaluations on knee stability and function, pain symptom by visual analogue scale (VAS), inflammatory parameters and so on. A total of 16 RCTs, including 1025 patients, were included for eligibility. Generally, the included studies were of low risk of bias, but the conducting of allocation concealment was not clearly described in many studies. Three imaging techniques, including MRI, CT and ultrasound, were selected in these trials. Significant improvement on graft remodeling, bone tunnel healing, harvest site healing and bone tunnel diameters were demonstrated in one of five (20.0%), three of five (60.0%), two of four (50.0%) and one of five (20.0%) studies respectively, for PRP group. Various clinical outcomes, such as IKDC score, Lysholm score, Tegner score, knee anteroposterior and rotational laxity, range of motion and VAS, could not be improved with PRP application. The PRP is associated with very limited role in improving knee outcomes following ACLR, and there is no indication for PRP procedures in ACLR at this stage.
Subject(s)
Anterior Cruciate Ligament Injuries , Anterior Cruciate Ligament Reconstruction , Platelet-Rich Plasma , Anterior Cruciate Ligament Injuries/surgery , Anterior Cruciate Ligament Reconstruction/methods , Humans , Knee Joint , Randomized Controlled Trials as Topic , Treatment OutcomeABSTRACT
Herein, a magnetic three-dimensional acanthosphere-like hierarchical Co@graphitic carbon (3D Co@GC) is introduced as an efficient adsorbent for extraction of three nitroimidazoles (NMZs: metronidazole (MNZ), ornidazole (ONZ) and tinidazole (TNZ)) from environmental water and food samples. The proposed 3D Co@GC was synthesized by a simple template-free method, which consisted of plentiful freely arranged one-dimensional nanowires. The adsorption properties of 3D Co@GC for three NMZs were investigated systematically by adsorption kinetic and isotherm studies. 3D Co@GC exhibits good adsorption capacity and fast adsorption kinetics toward three NMZs by virtue of its unique hierarchical structure. In addition, it was also found that a bit of methanol can effectively elute the adsorbed NMZs, eliminating the need for other dangerous strong acid or base solutions. Thus, 3D Co@GC as adsorbent to extraction three trace NMZs followed by direct quantification detection of targets with high-performance liquid chromatography with ultraviolet-visible detector (HPLC-UV) was developed. The parameters of dispersed magnetic solid-phase extraction (d-MSPE) were optimized by univariate and multivariate methods (Box-Behnken design). This established method revealed wide linear range and low limits of detection. Furthermore, the satisfactory recoveries of NMZs (86.7-106.7%) were acquired in spiked river water, honey, milk, and muscle samples. This study might provide a potential strategy for the efficient extraction and sensitive analysis of trace NMZs in river water, honey, milk, and muscle samples.
Subject(s)
Graphite , Nitroimidazoles , Adsorption , Carbon , Chromatography, High Pressure Liquid/methods , Limit of Detection , Magnetic Phenomena , Nitroimidazoles/analysis , Solid Phase Extraction/methods , WaterABSTRACT
In this study, a novel composite membrane was developed by casting the mixed aqueous solution of chitosan (CS) and polyvinyl alcohol (PVA) on a glass fiber microporous membrane. The polymeric coating of a composite membrane containing amino groups and hydroxyl groups has a favorable CO2 affinity and provides an enhanced CO2 transport mechanism, thereby improving the permeance and selectivity of CO2. A series of tests for the composite membranes were taken to characterize the chemical structure, morphology, strength, and gas separation properties. ATR-FTIR spectra showed that the chemical structure and functional group of the polymer coating had no obvious change after the heat treatment under 180 °C, while SEM results showed that the composite membranes had a dense surface. The gas permeance and selectivity of the composite membrane were tested using single gases. The results showed that the addition of chitosan can increase the CO2 permeance which could reach 233 GPU. After a wetting treatment, the CO2 permeance (454 GPU) and gas selectivity (17.71) were higher than that of dry membranes because moisture promotes the composite membrane transmission. After a heat treatment, the permeance of N2 decreased more significantly than that of CO2, which led to an increase in CO2/N2 selectivity (10.0).
ABSTRACT
Most economically important tungsten (W) deposits are of magmatic-hydrothermal origin. The species and partitioning of W during fluid exsolution, considered to be the controlling factors for the formation of ore deposits, are thus of great significance to investigate. However, this issue has not been well addressed mainly due to the significant difference in reported partition coefficients (e.g., from strongly incompatible to strongly compatible) between fluid and melt (DWfluid/melt). Here, we used an in situ Raman spectroscopic approach to describe the W speciation, and to quantitatively determine the Dfluid/melt of individual and total W species in granite melts and coexisting Na2WO4 solutions at elevated temperatures (T; 700-800 °C) and pressures (P; 0.35-1.08 GPa). Results show that WO42- and HWO4- are predominant W species, and the fractions of these two species are similar in melt and coexisting fluid. The partitioning behaviors of WO42- and HWO4- are comparable, exhibiting strong enrichment in the fluid. The total DWfluid/melt ranges from 8.6 to 37.1. Specifically, DWfluid/melt decreases with rising T-P, indicating that shallow exsolution favors enrichment of W in evolved fluids. Furthermore, Rayleigh fractionation modeling based on the obtained DWfluid/melt data was used to describe the fluid exsolution processes. Our results strongly support that fluid exsolution can serve as an important mechanism to generate W-rich ore-forming fluids. This study also indicates that in situ approach can be used to further investigate the geochemical behavior of ore-forming elements during the magmatic-hydrothermal transition, especially for rare metals associated with granite and pegmatite.
ABSTRACT
Background: Functional constipation (FCon), is a symptom-based functional gastrointestinal disorder without an organic etiology and altering brain structure and function. However, previous studies mainly focused on isolated brain regions involved in brain plasticity. Therefore, little is known about the altered large-scale interaction of brain networks in FCon. Methods: For this study, we recruited 20 patients with FCon and 20 healthy controls. We used group independent component analysis to identify resting-state networks (RSNs) and documented intra- and inter-network alterations in the RSNs of the patients with FCon. Results: We found 14 independent RSNs. Differences in the intra-networks included decreased activities in the bilateral caudate of RSN 3 (strongly related to emotional and autonomic processes) and decreased activities in the left precuneus of RSN 10 (default mode network). Notably, the patients with FCon exhibited significantly decreased interactive connectivity between RSNs, mostly involving the connections to the visual perception network (RSN 7-9). Conclusion: Compared with healthy controls, patients with FCon had extensive brain plastic changes within and across related RSNs. Furthermore, the macroscopic brain alterations in FCon were associated with interoceptive abilities, emotion processing, and sensorimotor control. These insights could therefore lead to the development of new treatment strategies for FCon.
ABSTRACT
Diabetes has been associated with postoperative complications, such as increased risk of tissue infection and impaired tissue repair caused by destabilization of hypoxia-inducible factor-1α (HIF-1α). Consequently, it is imperative to fabricate anti-bacterial and pro-regenerative small-diameter vascular grafts for treating cardiovascular disease in diabetic patients. Herein, we developed electrospun cobalt ion (Co2+)-loaded poly (ε-caprolactone) (PCL) microfiber vascular grafts (PCL-Co grafts). The released Co2+ significantly increased the stabilization of HIF-1α in high-glucose (HG)-treated HUVECs (HG-HUVECs) and macrophages (HG-macrophages). This resulted in enhanced cell migration, nitric oxide production, and secretion of bioactive factors by HG-HUVECs, and polarization of HG-macrophages toward M2 phenotypes in vitro. The Co2+ also conferred anti-bacterial properties to the grafts, while not perturbing the inherent anti-bacterial activities of HG-macrophages. Following abdominal artery implantation into type 2 diabetes mellitus (T2DM) rats, PCL-Co grafts were evaluated for performance in infection (grafts pre-contaminated with Staphylococcus aureus) and prophylaxes models (grafts alone). PCL-Co grafts prevented the incidence of subsequent infection in prophylaxes model and effectively inhibited the bacterial growth in the infection model. PCL-Co grafts also significantly enhanced cellularization, vascularization, endothelialization, contractile SMC regeneration and macrophages polarization in both models. Collectively, PCL-Co grafts exhibited the potential to combat infection and improve tissue regeneration under diabetes conditions.
Subject(s)
Cobalt , Diabetes Mellitus, Type 2 , Rats , Animals , Polyesters , Blood Vessel Prosthesis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic useABSTRACT
Mechanistic understanding of the topological cues delivered by biomaterials in promotion of oriented tissue regeneration (e.g., peripheral nerve regrowth) remains largely elusive. Here, we engineered nerve conduits composed of oriented microfiber-bundle cores and randomly organized nanofiber sheaths to particularly interrogate the regulatory mechanism of microfiber orientation on promoted peripheral nerve regeneration. With comprehensive yet systematic analyses, we were able to elucidate the intricate cascade of biological responses associated with conduit-assisted nerve regrowth, i.e., oriented microfibers facilitated macrophage recruitment and subsequent polarization toward a pro-healing phenotype, which in turn promoted Schwann cell (SC) migration, myelinization and axonal extension. Pronounced improvement of nerve regeneration in rat sciatic nerve injury was evidenced with enhanced electrophysiologic function, sciatic functional index and alleviated muscle atrophy 3 months post-implantation. The obtained results offer essential insights on the topological regulation of biomaterials in functional nerve tissue regeneration via immune modulation.
Subject(s)
Peripheral Nerve Injuries , Sciatic Nerve , Animals , Macrophages , Nerve Regeneration , Peripheral Nerve Injuries/therapy , Rats , Schwann CellsABSTRACT
OBJECTIVE: The T2 value of lumbar cartilage endplates was measured using the T2 mapping imaging technique, aiming to explore the correlation between the T2 value and Pfirrmann grading of intervertebral discs. METHODS: A total of 130 patients with lumbar spine MR examination due to persistent low back pain were enrolled, including 71 men and 59 women (age: 21-63 years). Lumbar Modic changes and Schmorl nodules were recognized by conventional T1WI and T2WI images in 49 patients, and these patients were excluded from the study. A total of 81 patients were enrolled in this study, including 45 men (45.16 ± 12.20 years) and 36 women (43.33 ± 11.27 years). Pfirrmann (Pm) grading of each lumbar disc was performed based on conventional T2WI median sagittal images and the position of cartilage endplates (CEP) was determined by IDEAL-SPGR images. Meanwhile, the T2 mapping technique was used to obtain T2 values of cartilage endplates. The T2 values of CEP corresponding to different Pm grade discs were compared, and the correlation between the T2 value and the Pm grade of intervertebral discs was analyzed. RESULTS: The T2 values of cephalic and caudal CEP of L1-2 in Pm grades I-II, Pm grades III, and Pm grades IV-V were 61.96 ± 5.89 ms, 54.45 ± 3.29 ms, 42.47 ± 3.69 ms and 64.35 ± 5.93 ms, 55.28 ± 3.97 ms, 44.75 ± 2.12 ms, respectively. For cephalic and caudal CEP of L2-3 , the T2 values in Pm grades I-II, Pm grades III, and Pm grades IV-V were 62.96 ± 6.93 ms, 55.19 ± 4.02 ms, 48.67 ± 4.56 ms and 65.51 ± 6.49 ms, 57.16 ± 5.55 ms, 52.05 ± 4.20 ms, respectively. The T2 values of cephalic and caudal CEP from L3-4 to L5 -S1 in Pm grades I-II, Pm grades III, and Pm grades IV-V were (63.72 ± 5.76 ms, 53.96 ± 6.52 ms, 48.05 ± 5.00 ms), (65.46 ± 6.37 ms, 55.70 ± 7.50 ms, 48.10 ± 3.27 ms); (66.34 ± 7.68 ms, 56.76 ± 9.48 ms, 47.80 ± 4.33 ms), (64.44 ± 4.65 ms, 59.30 ± 8.80 ms, 47.30 ± 5.78 ms), (65.32 ± 5.11 ms, 55.33 ± 6.65 ms, 48.18 ± 5.37 ms), and (63.47 ± 4.92 ms, 50.32 ± 8.86 ms, 44.77 ± 4.69 ms), respectively. There were significant differences in T2 values of cartilage endplates between the Pm grades I-II, III, and IV-V of intervertebral discs (P = 0.000). T2 values corresponding to Pm I-II grades were higher than those in Pm III grade, while T2 values in Pm grades IV-V were lowest. The T2 value of the L4-5 , L5 -S1 segment endplates was highly correlated with the Pm grades (r = -0.711, -0.721, -0.796, -0.745; P = 0.000) and that of L1-2 , L2-3 endplates were moderately correlated (r = -0.542, -0.562, -0.637, -0.612; P = 0.000). CONCLUSION: The T2 values of cartilage endplates revealed varying degrees of degeneration of intervertebral discs, and more severe degeneration corresponded to lower T2 values. Measurement of changes in the T2 value through cartilage endplates can be useful for the diagnosis of early intervertebral disc degeneration and the prevention of disc degeneration.
Subject(s)
Cartilage/diagnostic imaging , Intervertebral Disc Degeneration/diagnostic imaging , Low Back Pain/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Magnetic Resonance Imaging , Adult , Female , Humans , Intervertebral Disc Degeneration/classification , Low Back Pain/classification , Male , Middle Aged , Young AdultABSTRACT
A promising new form-stable phase change material (PA/PB) was fabricated using pinecone biochar (PB) as the supporting material of palmitic acid (PA). The biochar of PB with large surface area was produced by forest residue of pinecone, and it was cheap, environment friendly and easy to prepare. The PB was firstly utilized as the supporter of PA and the characterizations of PA/PB were analyzed by the BET, SEM, XRD, DSC, TGA, FT-IR and thermal conductivity tester. The results demonstrated that the PA was physically absorbed by the PB and the crystal structure of the PA was not destroyed. The results of DSC showed that the fusing and crystallization points of the form-stable phase change material with the maximum content of PA (PA/PB-4) were 59.25 °C and 59.13 °C, and its fusing and freezing latent heat were 84.74 kJ/kg and 83.81 kJ/kg, respectively. The results of TGA suggested that the thermal stability of the PA/PB-4 composite was excellent, which could be used for the applications of thermal energy storage. Furthermore, the thermal conductivity of PA/PB-4 was 0.3926 W/(mâK), which was increased by 43.76% compared with that of the pure PA. Thus, the study results indicated that the PA/PB-4 had great potential for thermal energy storage applications.