Thiol-ene chemistry incorporates a new spiropyran-containing polyurethane ionogel with photochromic, photomechanical and photoconductive properties.

The photocuring technology based on thiol-ene click reaction can be easily applied for copolymerizing or crosslinking the acrylate monomers for ionogels. However, there is still a problem: when the acrylate monomers contain the popular spiropyran as the stimuli-responsive group, it should be concerned about the participation of the active CC bond from the ring-opened spiropyran during a thiol-ene reaction, which may in turn affect the stimuli-responsiveness of the spiropyran. Up to now, the structure and properties of spiropyran-containing ionogels in this case have still not been well investigated. Therefore, in this work we carefully study a new spiropyran-containing polyurethane ionogel by crosslinking an acrylate-terminated, spiropyran-containing polyurethane prepolymer and a polythiol in ionic liquid through thiol-ene chemistry. It is found for the first time that, during constructing an ionogel, the coexistence of a reversible thiol-ene reaction between the CC bond from the ring-opened spiropyran and the thiol group can bring about a different reverse photochromic behavior. The proposed mechanism of the abnormal photochromism is analyzed. In addition, it is also observed that the thiol-ene chemistry can incorporate photomechanical and photoconductive properties into the new spiropyran-containing ionogel.

[Study of the last glacial loess-like deposits in the coastal area of South China with diffuse reflectance spectroscopy and laser particle size analysis].

Newly discovered yellow silt widely distributed in the coastal area of south China was analyzed using diffuse reflectance spectroscopy (DRS) and laser particle size (LPS) methods in the present paper. The authors take the lead in trying to synthetically judge the depositional environment, transporting agent and forming mechanism of the yellow silt from angles of output forms of iron minerals as well as grain size distribution features of the samples chose from three representative sections and a drill core. The DRS first derivative curves show the peak height of iron minerals decreasing from hematite (565 nm) to goethite (505 and 435 nm), which reflects a relatively dry, cold climate that coincides with the aeolian loess widely distributed in the northwest China, but reverses of the fluvial and marine deposits which experienced a well hydration in humid conditions over a long period of time in study area. LPS analysis show that grain size from top to bottom of the sections and drill core are homogeneous and typical of aeolian sediments. The grain size distribution in the yellow silt is characterized by double peaks with main peak of 10-50 µm and a secondary peak of < 5 µm, similar to that of loess in northwest China but quite different from associated fluvial and marine deposits featured by unidirectional change of allocation mode of the grain size groups. Based on grain size analysis, DRS results, age range of 10-80 ka, and spatial distribution that both of the positive landforms and buried topographies in the coastal area of south China have this kind of sediments, the yellow silt is considered to represent an aeolian deposit formed during the last glacial period, which is called "loess-like deposits" in our study.

[Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

[Experimental study of the red-bed pigment with diffuse reflectance spectroscopy].

Red pigment of continental red-bed is known originating from the fine-particle hematite in the rocks. Advance of researches on the origin of continental red-bed demonstrates that the red pigment of red-bed originated from its diagenetic but not depositional process. The high diagenetic temperature causes the dehydration of iron hydrate to form hematite, generating the red pigment. For examining the above hypothesis, the authors of this paper designed an experiment to approach the reddening process, i.e. formation of the red pigment of continental red-bed. Black ooze sampled from the Holocene sediments of the Pearl River Delta was heated in different ways. The diffuse reflectance spectroscopy (DRS) of those heated ooze samples were detected with Perkin-Elmer Lamdba 950 ultraviolet/visible/near-infrared spectrophotometer, and moreover, red-values of the samples were calculated for determining their coloring levels. Iron in black ooze sediment is predominantly in the form of goethite. Experimental results verified that initial dehydration-temperature of goethite is about 150 degrees C, either enhancing temperature or prolonging heating time is accompanied with decreasing goethite and increasing hematite, and a positive relationship exists between red-value of samples and peak-height of hematite. The experimental results strongly support the idea of thermal origin of continental red-bed.

[Comparison of fluorescence spectroscopy and plasma-mass spectrometry results of the Meso/Cenozoic basic rocks in SE China and its geo-implication].

With comparison of the fluorescence spectroscopy and plasma-mass spectroscopy analysis results of the Meso/Cenozoic basic rocks of SE China, the authors found that the average SiO2 content of the Mesozoic basic rocks in this area is about 50%, while that of the Cenozoic basic rocks is about 43%. The former belongs to the basic group and the later to the ultrabasic group in igneous rock classification. Cenozoic basalts, accompanied with high magnesium content and low silica-alumina component, are obviously basic or ultrabasic rocks. Distinctive difference in the content of trace elements and of REE is also presented between the Mesozoic and the Cenozoic basic rocks. Distribution models of both trace elements and REE of the Mesozoic basic rocks are similar to those of the upper crust, and the models of the Cenozoic basic rocks are like those of OIB, indicating that basic rocks of the Cenozoic and OIB should originate from the mantle while that of the Mesozoic is from the bottom part of the upper crust with relationship to the evolution of the Mesozoic crustal magma layer of this area.

[Discussion on diagenesis of Xilingang pluton-constrained by X-ray Fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy].

The results on Xilingang pluton, mainly consisting of red beds, granites containing numerous debris of red beds and granites, obtained by X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy show: (1) Xilingang pluton from red beds, granites containing numerous debris of red beds to granites has obvious characteristics of decreasing silicon and alkali content, and rising ignition loss, dark mineral content and oxidation index; (2) Chondrite-normalized REE distribution curves and primitive mantle-normalized spider diagram for trace elements of redbed, granites containing numerous debris of red beds and granites have a good consistency, the distribution characteristics of elements are similar to Nanling transformation-type granite; (3) The value of Raman spectrogram characteristic peak of quartz crystal in Xilingang granite decreased from the center of quartz crystal, and FWHM is steady. According to the above, the authors believe that Xilingang granite formed was related to in-situ melting of red beds and underlying strata and magma consolidation. Volatile components were discharged continuously, and oxidation index decreased gradually in the melting process. In the process of diagenesis, the top of pluton tend to be an ongoing silicon and alkali increase, while TFeO and MgO continue to migrate to bottom, and crystallization environment is a relatively closed and steady system.

Short-term Effectiveness of a Modified Osteotomy for Total Elbow Joint Replacement in Patients of Hemophilic Elbow Arthritis with Severe Flexion Contracture Deformity: A Three-Cases Series Report.

OBJECTIVE: To report the modified osteotomy and the short-term effectiveness of the total elbow joint replacement in patients of hemophilic elbow arthritis with severe flexion contracture deformity. METHODS: This study introduced the therapeutic approach of the total elbow joint replacement in patients of hemophilic elbow arthritis with severe flexion contracture deformity, and assessed the short-term effectiveness in three cases (three elbows) of end-stage hemophilic elbow arthritis admitted from October 2020 to December 2020. The included patients were all diagnosed with hemophilia A (factor VII deficiency), accompanied by severe bilateral elbow joint flexion contracture, which seriously affects daily life and requires surgical intervention. Clinical data and follow-up results were analyzed before total elbow arthroplasty and 1, 3, and 6 months postoperatively. Pre- and postoperative range of motion, pain score, and function score were compared, and intraoperative and postoperative complications are reported. RESULTS: All three patients were male, with an average age of 31 years. The main clinical manifestations were bilateral elbow arthritis with flexion contracture. Two of the patients underwent right elbow replacement, and one patient underwent left elbow replacement. All cases were followed up for 6 months postoperatively. No incision infection or ulnar nerve injury occurred. Postoperative triceps brachii muscle strength was slightly weakened compared with preoperative muscle strength. Average elbow flexion and extension range of motion was 60° (30°-100°) preoperatively and increased to 127° (110°-140°) postoperatively; rotational range of motion of the affected forearm was 47° (10°-85°) preoperatively and increased to 117° postoperatively. The mean visual analogue scale (VAS) was 6 (5-8) preoperatively and decreased to 3 (2-4) postoperatively. The mean MEPS score was 62 (55-75) and increased to 87 (80-95) postoperatively. During the follow-up, anteroposterior and lateral radiographs showed no signs of prosthesis loosening in the elbow. CONCLUSIONS: For severe hemophilic elbow arthritis patients, the short-term treatment effect of total elbow replacement is good, following the strict adherence to the surgical indications and proper preparation for the perioperative period. The modified osteotomy can fully expose the visual field and reduce complications of ulnar nerve injury. The long-term effects need to be study future.

HIV infection is not associated with perioperative blood loss in patients undergoing total hip arthroplasty.

BACKGROUND: Patients with HIV have a higher prevalence of thrombocytopenia than those without HIV infection, increasing their risk of substantial perioperative blood loss (PBL) during total hip arthroplasty (THA). This study aimed to evaluate PBL risk factors in HIV-infected patients undergoing THA. METHODS: Eighteen HIV+ patients (21 hip joints) and 33 HIV- patients (36 joints) undergoing THA were enrolled in this study. PBL was calculated using the Gross equation, which comprises total blood loss (TBL), dominant blood loss (DBL), and hidden blood loss (HBL). Risk factors for post-THA PBL in both patient populations was evaluated using multivariable linear regression. RESULTS: At baseline, the HIV+ patients were younger, more likely to be male and to have elevated hemoglobin and albumin levels, and lower erythrocyte sedimentation rates than HIV- patients. There were no differences in the T-lymphocyte subsets or coagulation function between the two groups. Age and albumin level were identified as potential HBL risk factors after THA, and albumin level was associated with higher TBL. The unadjusted linear regression analysis showed that the HBL and TBL were significantly higher in HIV+ patients than in HIV- patients. However, after adjusting for other factors, no differences in DBL, HBL, or TBL were observed between HIV- and HIV+ patients. CONCLUSION: PBL was similar in both groups undergoing THA, regardless of their HIV-infection status. THA surgery is a safe and effective procedure in HIV+ patients.

Clinical significance of articulating facet displacement of lateral atlantoaxial joint on 3D CT in diagnosing atlantoaxial subluxation.

BACKGROUND/PURPOSE: To improve the recognition of articulating facet displacement of lateral atlantoaxial joint (AFDLAJ), and to evaluate the significance of AFDLAJ in diagnosing atlantoaxial subluxation. METHODS: The three-dimensional computed tomography (3D CT) imaging findings of 54 patients with atlantoaxial subluxation were retrospectively analyzed, and the imaging features of AFDLAJ were discussed. All the patients were examined in neutral position, and 25 in an additional rotary position. 3D images of the atlantoaxial joints were obtained by surface shade display and volume rendering. The diagnostic results of 3D CT, routine CT and X-ray were compared. RESULTS: All the 54 patients with atlantoaxial subluxation were correctly diagnosed by 3D CT with no suspicious or missed diagnoses, including 38 cases of rotatory subluxation, 11 of anterior subluxation and five of posterior subluxation. AFDLAJ was found in all the 54 patients in neutral position, with the extent of subluxation between 2.0 mm and 9.0 mm. Among the 25 cases in rotary position, rotational fixation was found in 10 cases and rotational asymmetry in 15. The diagnostic accuracy of 3D CT was higher than that of X-ray or routine CT. CONCLUSION: Once AFDLAJ appears in neutral position and rotational fixation or asymmetry in rotary position, atlantoaxial subluxation can be ascertained, as well as the type and extent of subluxation, and fake subluxation due to the heads rotation or normal lateralized odontoid can be excluded. AFDLAJ is a vital direct sign in diagnosing atlantoaxial subluxation.