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Oxybenzone (OBZ), a widely used sunscreen additive, has damaging effects on corals and plants. This study demonstrated that OBZ significantly inhibited photosynthesis and growth of cucumber (Cucumis sativus L.) seedlings. Combined analyses of chlorophyll fluorescence and 820-nm reflection suggested that OBZ severely inhibited photosynthetic electron transport (PET) from QA to cytochrome b6f (Cyt b6f) complex, restricting the reduction of the reaction center in PSI. Separate measurements of PSI and PSII PET in chloroplasts indicated that OBZ inhibited the PET of neither PSII nor PSI, but it severely inhibited the whole linear PET. We thus confirmed that the inhibition of PET by OBZ was due to the inhibition of plastoquinones (PQs) and/or the Cyt b6f complex between PSI and PSII. PET is essential for producing ATP and NADPH used in CO2 assimilation. Therefore, limiting the use of sunscreens containing OBZ is significant in protection of aquatic and terrestrial ecosystems and ensuring the safety of agricultural production. [ABSTRACT FROM AUTHOR]

In this paper, the solidification process of eleven tons flat steel ingot is simulated by the finite element analysis software PROCAST, and the solidification state of the ingot with and without chassis is analyzed and compared. The results show that the forced cooling chassis makes low temperature area of the bottom ingot enlarged. And it has little influence on the temperature field and the solidification speed of the upper ingot. For the small flat steel ingot, the forced cooling chassis will deteriorate the shrinkage. [ABSTRACT FROM AUTHOR]

The microstructure, magnetic and magnetocaloric properties are investigated in the melt-spun and annealed Ni42.9Co6.9Mn38.3Sn11.9 ribbons. The columnar grains grow perpendicular to ribbon surfaces. After annealing, the grain size increases greatly. Meanwhile, the parent phase is suppressed and therefore L10 martensite predominates, indicating obvious shift of martensitic transformation to high temperature. More interestingly, the martensite variants are distinctly observed on the fractured cross-section of annealed ribbons, not just on the free surface in general. The significant enhancement of magnetic entropy change and effective refrigerant capacities with relatively smaller thermal hysteresis make annealed ribbons potential candidate in magnetic refrigeration around room temperature. [ABSTRACT FROM AUTHOR]

In this paper, cooling plan is optimized to solve the central porosity problem of 450 mm diameter steel electrode ingot. The central porosity of ingot in corresponding cooling plans is calculated by the finite element analysis software ProCAST. The results show that in the plan of independent riser and strengthened cooling in lower ingot part, the central porosity has been significantly reduced. [ABSTRACT FROM AUTHOR]

The global climate system has experienced a series of drastic changes during the Cenozoic. These include the climate transformation in Asia, from a zonal pattern to a monsoon-dominant pattern, the disappearance of subtropical aridity related to a planetary circulation system and the onset of inland deserts in central Asia. Despite of the major advances in the last two decades in characterizing and understanding these climate phenomena, disagreements persist relative to the timing, behaviors and underlying causes. This paper addresses these issues mainly based on two lines of evidence. Firstly, we newly collected the available Cenozoic geological indicators of environment in China to compile the paleoenvironmental maps of ten intervals with a more detailed examination within the Oligocene and Miocene. In confirming the earlier observation that a zonal climate pattern was transformed into a monsoonal one, the new maps within the Miocene indicate that this major change was achieved by the early Miocene, roughly consistent with the onset of loess deposition in China. Although a monsoon-like regime would have existed in the Eocene, it was restricted in the tropical-subtropical regions. The observed latitudinal oscillations of the climate zones during the Paleogene are likely attributable to the imbalanced evolution of polar ice-sheets between the two hemispheres. Secondly, we examine the relevant depositional and soil-forming processes of the Miocene loess-soil sequences to determine the circulation characteristics with special emphasis given to the early Miocene. Continuous eolian deposition in the middle reaches of the Yellow River since the early Miocene firmly indicates the formation of inland deserts, which has been constantly maintained in the past 22 Ma. Inter-section grain-size gradients indicate northerly dust-carrying winds and source location, as is regarded as the main criteria of the Asian winter monsoon system. Meanwhile, the well-developed Luvisols evidence the existence of circulations from the ocean, which brought moisture to northern China. These imply the coexistence of two kinds of circulations, one from the ocean as moisture carrier and another from the inland deserts as dust transporter. The accretionary properties of the early Miocene paleosols, resulted from interactive soil-forming and dust deposition processes, evidence two seasonally alternative circulations, i.e. a monsoonal climate regime. The much stronger development of the early Miocene soils compared to those in the Quaternary loess indicates significantly stronger summer monsoons. These lines of evidence indicate a joint change in circulations and inland aridity by the early Miocene, and suggest a dynamic linkage of them. Our recent numerical experiments reconfirm the potential roles of Tibetan uplift and Paratethys shrinkage in triggering this major climate reorganization, as revealed in peer studies, but yielded more details about their combined scenarios. These two factors would have coacted with the help of South China Sea spreading. Although the realistic effects of each factor remain to be further discriminated, probably through more paleoaltimetrical and tectonic approaches, the Miocene loess record provides a vital insight that tectonics had evolved to a threshold by the early Miocene to cause this major climate reorganization in Asia. [ABSTRACT FROM AUTHOR]

In this paper, the temperature field and heat transfer stress mathematical model of the unidirectional solidification ingot of the traditional water-cooled chassis and the improved water-cooled chassis are established, and the numerical simulation calculation of 45 tons unidirectional solidification ingot is carried out by using the finite element simulation analysis method. The results show that adding proper forced cooling conditions to the bottom of ingot is beneficial to the balanced advance of the solidification front of molten steel. The improvement of the bottom forced cooling scheme obviously shortens the solidification time of the ingot. The water cooling at the bottom of the ingot is adapted to the air gap distribution to achieve uniform air gap distribution. The ingot solidifies evenly in the longitudinal direction to avoid bottom warpage. [ABSTRACT FROM AUTHOR]

In this paper, the effect of exothermic riser on ingot solidification is studied by numerical simulation. Through the study, it is concluded that the combustion of exothermic risers delayed the solidification of steel in riser, and the solidification time increased significantly, extending about 8 143 / s. In the later stage of solidification, the temperature isotherm of the ingot is smoother than that of the ordinary ingot, making the angle of the solidification front larger, which is conducive to feed. The shrinkage of the ingot with heat riser is better than that of the common ingot. The shrinkage above 10% of the ingot is almost not found in the ingot with exothermic riser, and the shrinkage of the ingot is mainly concentrated above the riser line. And it obviously improves the internal quality of the ingot. [ABSTRACT FROM AUTHOR]

Objective: To analyze the factors related to the need for revision surgery due to nonunion or internal fixation failure after the treatment of distal femoral fracture with lateral locking plate (LLP)., Methods: Retrospective analysis was made of the clinical data of 130 cases with distal femoral fracture treated in our hospital from March 2005 to March 2019. SPSS 17.0 software (univariate analysis and Logistic regression analysis) was used to analyze the general condition [gender, age, body mass index (BMI), comorbidities, smoking history], injury related factors (energy of injury, open or closed injury, AO/OTA classification of fracture, fracture area distribution), operation related factors (operation time, reduction quality, postoperative infection) and construct characteristics of internal fixation., Results: Twelve of 130 patients who were included in the study underwent revisional surgery, with a revision rate 9.2%. Univariate analysis showed that there were significant differences in age, BMI, AO/OTA classification, fracture area distribution, operation time, reduction quality, length of plate/fracture area, length of plate/fracture area above condylar between the two groups ( P < 0.05). Logistic regression analysis showed that AO/OTA classification (A3), supracondylar involved fracture, operation time, reduction quality and the length of the plate/fracture area above the condylar were the possible related factors ( P < 0.05). Destruction of the medial support ability of the femur in comminuted type A3 fracture, supra-condylar cortex area fracture involvement, increase of the bending stress of the LLP due to poor fracture reduction quality, damage of the blood supply of fracture end due to long-time operation, and stress concentration caused by insufficient length of plate might be risk factors of revisional operation after the treatment of distal femoral fracture with LLP. For the patients who needed revision after LLP treatment, additional use of medial minimally invasive plate fixation and autologous bone transplantation, change to intramedullary nail fixation were commonly used clinical treatment strategies., Conclusion: AO/OTA classification (A3), supracondylar involved fracture, long operation time, poor reduction quality and the length of the plate/fracture area above the condylar were the possible predictive factors of the revision in distal femoral fractures treated with lateral locking plate. The appropriate application of the locking plate and operation strategy are the key to reduce the revision rate in distal femoral fractures.

Objective: To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures., Methods: Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group ( n =92) and non-recurrent kyphosis group ( n =52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis., Results: The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation ( P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws ( P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences ( P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male ( OR : 2.88, 95% CI : 1.196-6.933), upper disc injury ( OR : 2.962, 95% CI : 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture ( P < 0.05)., Conclusion: The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Objective: To retrospectively analyze the risk factors of avascular necrosis of femoral head (ANFH) after internal fixation in young and mid-aged adults., Methods: From January 2007 to December 2017, femoral neck fracture patients (18-60 years old) treated by reduction and internal fixation were retrospectively studied in Peking University Third Hospital. We recorded their gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) grade, reason of injury, fracture side, interval between injury and surgery, location of fracture line, Garden classification, Pauwels classification, reduction method (open or closed), internal fixation and reduction quality. The diagnosis of ANFH was confirmed based on X-ray and MRI images during the follow-up. The internal fixation method included cannulated compression screw (CCS) or dynamic hip screw (DHS, with or without anti-rotation screw). χ 2 test and Logistic regression analysis were used to analyze the relationship between the various factors and postoperative ANFH., Results: A total of 113 patients were included in this study, including 63 males and 50 females with an average age of (43.17 ± 12.34) years. They were followed up by (25.08 ± 16.17) months. ASA grade included grade I (21 cases), grade II (55 cases) and grade III (37 cases). The reasons of injury included low-energy trauma (76 cases) and high-energy (37 cases). The fracture line included subcapital type (37 cases), transverse type (74 cases) and basal type (2 cases). Garden classification included type I (3 cases), type II (46 cases), type III (39 cases) and type IV (25 cases). Pauwels classification included type I (21 cases), type II (55 cases) and type III (37 cases). Interval between injury and surgery was (3.88 ± 3.66) days, 108 patients and 5 patients performed closed and open reduction respectively. 63 patients performed CCS, and 50 patients performed DHS. The reduction quality included grade A (91 cases), grade B (18 cases) and grade C (4 cases). 18 patients developed ANFH after surgery, the incidence rate was 15.93% (18/113). The result of χ 2 test showed the reason of injury (OR=0.19, P < 0.01), Garden classification (OR=0.13, P < 0.01), Pauwels classification (OR=0.12, P = 0.02), internal fixation method (OR=3.29, P = 0.04) and reduction quality (OR=0.33, P < 0.01) were significantly associated with ANFH. These five factors were further included into the Logistic regression analysis, and its results showed that the reason of injury (OR=4.11, P = 0.03) and Garden classification (OR=4.85, P = 0.04) were statistically significant., Conclusion: The reason of injury, Garden classification, Pauwels classification, internal fixation and reduction quality may increase the risk of ANFH after surgery, and the reason of injury and Garden classification were much more significant.

Objective: To study the clinical outcomes and characteristics of fracture healing of a modified internal fixation method, which was implemented by placing four and two screws respectively at the proximal and distal end of the locking plate in the minimally invasive percutaneous plate osteosynthesis (MIPPO) for patients with proximal humeral fractures., Methods: Patients in Peking University Third Hospital from February 2010 to December 2016 were brought into this retrospective study. Based on different operation methods, they were divided into minimally invasive (MI) group and non-minimally invasive (non-MI) group, and the patients in MI group were performed with the modified internal fixation. In order to observe the varying efficacy for different fracture types between the two groups, we further investigated the patients with Neer two-part and three-part fracture, respectively. The follow-up parameters included general physical examination, X-ray, visual analogue scale (VAS) and Constant-Murley score., Results: A total of 117 patients with an average age of (61.5±16.2) years met the inclusion criteria, and MI group included 45 patients, non-MI group included 72 patients. According to the Neer classification, there were 46 cases of two-part fracture, 63 cases of three-part fracture and 8 cases of four-part fracture. In MI group, there were 17 males and 28 males with an average age of (62.2±17.1) years, including 18 cases of two-part fracture, 23 cases of three-part fracture and 4 cases of four-part fracture. In non-MI group, there were 27 males and 45 females with an average age of (60.1±17.7) years, including 28 cases of two-part fracture, 40 cases of three-part fracture and 4 cases of four-part fracture. There were no significant differences between the two groups in terms of gender (P=0.975), age (P=0.545) and fracture type (P=0.756). The average hospital-stay in MI group and non-MI group was (2.8±1.1) days and (4.3±1.3) days (P=0.023), the operation time was (67.8±14.9) min and (102.3±34.1) min (P<0.001), the blood loss was (21.3±6.5) mL and (181.5±55.6) mL (P<0.001), the Constant-Murley score was 6.1±0.9 and 6.5±0.8 (P=0.032) one week after surgery, and the Constant-Murley score was 66.1±4.3 and 63.4±4.9 (P=0.006) three months after surgery, MI group had significant advantages in these aspects. In terms of Neer two-part and three-part fracture, the VAS score (5.9±0.8) one week postoperatively and the Constant-Murley score (66.6±3.7) three months postoperatively were significantly superior in MI group (P<0.05). In MI group, delayed fracture healing occurred in 1 case (2.2%) and abduction was restricted in 1 case (2.2%). In non-MI group, delayed fracture healing occurred in 3 cases (4.2%) and abduction was restricted in 2 cases (2.8%). There were no internal fixation complications and humeral head necrosis in both groups., Conclusion: Applying the modified internal fixation in MIPPO to cure proximal humeral fractures is effective clinically with thick callus formation occurring at the fracture site. The fracture can achieve normal healing and the shoulder functions can restore well, indicating the modified surgical method is a good treatment option.

Acid and pepsin-soluble collagen (ASC and PSC, respectively) were extracted from cod (Gadus macrocephaius) skin, and yields of 37.36 and 55.96% were obtained for ASC and PSC, respectively. The total yield of ASC and PSC was 93.92%, based on the lyophilized dry weight, which is higher than that obtained from other sources. Electrophoresis revealed that both ASC and PSC consisted of two different α-chains (α1 and α2), which were characterized as type I collagen. Analysis of amino acids showed that both the ASC and PSC contained imino acids (216.1 and 190.6 residues/1000 residues, respectively) and the Fourier transform infrared spectroscopy spectra of both collagens were similar with pepsin hydrolysis having no effect on their triple-helical structure. The thermal denaturation temperature of ASC and PSC, as measured by viscometry, was 26.8° and 25.6°C, respectively.