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Purpose: Intertrochanteric fractures are common among femoral fractures in the elderly population. The trochanteric nail is a standard internal fixator used in treating femoral intertrochanteric fractures. The technique of femoral fracture reduction affects the postoperative outcome. Here, we applied finite element analysis (FEA) to study mechanical effects of different reduction approaches using the trochanteric nail in treating both stable and unstable intertrochanteric fractures. Methods: We combined FEA and in vitro experiments using a digital imaging correlation (DIC) technique to study effects of different alignment conditions after treating 4 cases of intertrochanteric fractures using the trochanteric nail system. A downward force of 2250 N was applied to the femoral head, and the distal end of the femur was fixed. The observed indicators were the femur displacement, together with the stress on the femur and trochanteric nail system. In addition, the displacement distribution was analyzed using DIC. Results: In the case of space reduction, the force was transmitted by the trochanteric nail system, resulting in greater stress imposed on the femur or the trochanteric nail system. In the case of closed reduction, the stress was much smaller. In the case of unstable fracture reduction, closed reduction was associated with a smaller contact area at the fracture site, resulting in greater stress on both trochanter and the trochanteric nail system. Conclusion: When the trochanteric nail system was used for fixation, the fracture site was well aligned, reducing the stress on the femur or the trochanteric nail.

Purpose: The use of a locking plate eliminates excessive pressure on bone for anatomical reduction and thus preserves the periosteal blood supply, which is important for fracture healing. The far-cortical locking technique with a semi-rigid locking screw reduces structural stiffness and parallel motion, allowing uniform callus formation at the fracture site. Although previous studies demonstrated the superior clinical and biomechanical outcomes of semi-rigid locking screws over rigid ones, it is unclear whether a gap between the plate and bone should be preserved in the far-cortical locking technique. Methods: The present study conducted finite element analyses with mechanical calibration to clarify the influence of a plate-bone gap on the biomechanical performance of the far-cortical locking technique. A simulated mid-shaft fracture model was fixed using a locking plate and six semi-rigid locking screws. The plate-bone distance was 0 to 2 mm and the axial compressive load was 500 N. Results: Gliding guidance at the plate-bone interface enhanced parallel intersegmental motion but reduced intersegmental movement, which is a mechanical stimulant for callus formation, and may increase pressure on the bone. Screw stresses increased with increasing plate-bone gap distance. Conclusion: For the far-cortical locking technique, the results suggest a minor plate-bone gap should be preserved. Engagement between the plate and bone should be avoided both before and after the application of mechanical load.

The aim of this study was to evaluate the immunomodulatory effects of atractylodin, a polyethylene alkyne, on the maturation of bone marrow-derived dendritic cells (BM-DC) as well as its antirheumatic effect on collagen-induced arthritis (CIA) in DBA/1 mice. Our results indicate that atractylodin effectively suppressed the secretion of pro-inflammatory cytokines, expression of costimulatory molecules, and p38 MAPK, ERK, and NF-κBp65 signaling pathways in LPS-incubated dendritic cells (DCs). Additionally, the proliferation and cytokine secretion (IFN-γ and IL-17A) of CD8+and CD4+T cells were reduced. In a murine CIA model, intraperitoneal injection of atractylodin significantly alleviated the severity of the disease progression, as indicated by reduced paw swelling, clinical arthritis scores, and pathological changes of joint tissues. In addition, the overall proliferation of T cells stimulated by type II collagen and the abundance of Th1 and Th17 in the spleens were also significantly decreased with atractylodin treatments. Furthermore, atractylodin significantly downregulated the expression levels of CD40, CD80, and CD86 of DCs in the spleens. In conclusion, this study shows for the first time that atractylodin has potential to manipulate the maturation of BM-DCs and should be further explored as a therapeutic agent in the treatment of rheumatoid arthritis (RA).

Conventional shape-based proximity effect correction (PEC) methods can only improve pattern fidelity and present a risk to correction effectiveness under severe resist-contour distortions for electron-beam writers. Herein, a shape-based PEC method for effectively improving both the pattern fidelity and energy slope without the risk in realizing high throughput, fidelity, and contrast is presented. An extra-framed pattern added to the target pattern is optimized to achieve better trade-off between contrast improvement and writing-time reduction. The proposed method demonstrated significant improvements in lithographic performance compared with the conventional and dose-based PEC methods for high-numerical-aperture extreme-ultraviolet mask and aggressive patterns.

The solid acid catalyst (ACSA) for the gutter oil esterification to biodiesel was prepared via active carbon as raw material by introducing the-SO3H group onto the surface of it. The ACSA were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and elemental analysis (EA), respectively. And the results showed that the-SO3H groups were successfully introduced onto the surface of the active carbon and the containing of the-SO3H groups are higher than 0.017g per gram of ACSA.

The urethane reaction of o-hydroxybenzyl alcohol with phenyl isocyanate was monitored with in situFT-IR. Dibutyltin dilaurate was used as catalyst and its amount effect was investigated. It was found that there was an obvious induction period before reaction began. It was interesting that the time of induction period climbed up and then declined with the increase of dibutyltin dilaurate. When the concentration of dibutyltin dilaurate reached 9.58×10−5mol/L, the induction period disappeared completely and hereafter did not appear any more. Furthermore, the urethane reaction kinetics was studied. When the concentration of dibutyltin dilaurate increased, the reaction rate of phenolic group (k1) increased sharply, but the reaction rate of alcoholic group (k2) appeared of little change on the whole. k1increased about 20-fold, yet k2increased about 2-fold when the concentration of dibutyltin dilaurate varied from 9.58×10−6mol/L to 1.92×10−4mol/L, which made the value of k1/k2enlarge.

Abstract: Objective: To discuss the epidemic strength of cardia and distant stomach cancers in the high risk region of esophageal cancer along the south Taihang mountain such as in Shexian, Linxian, and Cixian Counties, and to clarify the tasks for the control of upper gastrointestinal tract cancer as a whole in the region. Methods: Comparisons of incidence and mortality rates of esophageal, cardia and stomach cancers were made between Cixian, Linxian and Shexian Counties with reference to detection rates of cancer in situ and precancerous lesions of the three upper gastrointestinal cancers by endoscopic screening. The screening was performed from 1999 through 2004 in the three adjacent counties including a total of 6233 local residents aged 40 to 69 years old. Results: The incidence rates for cardia cancer for the male and female from 2000 through 2004 were 69.9 and 41.5, and the mortality rates were 54.3 and 33.2 respectively in Shexian County. Esophageal, cardia, and stomach cancers constitute about 70∼80 percent of all malignant disease by incidence or mortality rates. Endoscopic survey with iodine staining can effectively detect squamous cell precancerous lesions in the esophagus, but the method is inadequate for the detection of adeno precancerous lesions of the cardia and stomach. Conclusion: The south Taihang mountain region is a high risk area not only for esophagus cancer, but also for cardia and stomach cancers. To control upper gastrointestinal tract cancers as a whole in the region, special attention should be paid to the control of cardia and stomach cancers. Presently, to find effective screening methods for detecting cardia and stomach precancerous lesions is especially important.