The Toxicity and Antibacterial Effects of Povidone-Iodine Irrigation in Fracture Surgery.

OBJECTIVE: Surgical site infection is a common complication of surgery, especially in orthopedics. Povidone-Iodine (PI) is one of the oldest and most commonly used disinfectants in surgery. However, the toxicity and antimicrobial effect of PI have not been discussed. In addition, no study has explored the optimum PI concentration for sterilization and tissue healing. This study explores the germicidal efficacy of different concentrations PI, in addition, the toxicity and antibacterial effects of PI irrigation in fracture surgery are also discussed. METHODS: Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa) were used to evaluate the germicidal efficacy of PI in vitro and in vivo. In vitro, the effects of PI on bacterial growth were analyzed. 2.5%, 1.25%, 0.5%, 0.25%, 0.05%, 0.025%, 0.005%, 0.0025% and 0% PI was added into the bacterial suspension, besides, the bacterial algebra and growth rate were tested. Meanwhile, the fluorescence intensity of viable bacteria was also tested to evaluate the effects of PI on bacterial survival. In vivo, first, femoral fracture with wound infection rat models were established. Second, thyroid gland sections, blood thyroxine, urinary iodine, wound local skin, muscle and bone tissue sections, serum creatinine and alanine aminotransferase, serum and bone local tissue interleukin-6 (IL-6), interleukin-10 (IL-10), bone morphogenetic protein (BMP-2), vascular endothelial growth factor (VEGF) and transforming growth factor (TGF-ß1) were detected in rat femoral shaft fracture model with 5%, 2.5%, 0.5%, 0.05%, and 0% PI irrigation. Third, tissue bacteria culture was tested in rat femoral fracture with wound infection model with different concentrations PI irrigation. RESULTS: In vitro, 2.5%, 1.25%, 0.5% PI inhibited the growth of bacteria. 1.25%, 0.5% PI killed all the bacteria, while 0.25%, 0.05% PI had not killed bacteria after about 10 min. The iodine absorption of 5%, 2.5%, 0.5% PI irrigation did not cause thyroid injury. The 5%, 2.5%, 0.5% PI irrigation did not make serum creatinine and alanine aminotransferase abnormal and can remove bacteria from wounds. The 0.5%, 2.5% PI irrigation can promote tissue healing and increase BMP-2, VEGF, TGF-ß1, IL-10, in addition, decrease IL-6. 5% PI irrigation would inhibit tissue healing, and increase IL-6, decrease BMP-2, VEGF, TGF-ß1, IL-10. CONCLUSIONS: Povidone-Iodine was a widely used disinfectant and 2.5%, 1.25% and 0.5% PI could effectively kill bacteria. Five percent and lower concentration PI irrigation was safe and could not cause thyroid, kidney and liver damage. The 0.5% PI irrigation was beneficial for tissue healing but 5% PI irrigation was the opposite.

Pore Structure Characteristics and Controlling Factors of a Tight Sandstone Reservoir in the Paleogene Shahejie Formation, Nanpu Sag, Bohai Bay Basin, China.

Tight sandstone reservoirs have ultralow physical properties and strong heterogeneity, and there is a need to describe the corresponding pore structure characteristics systematically to promote research on unconventional reservoirs. The pore structure, controlled by the diagenesis and volcanic activity of the tight reservoirs in the third member of the Shahejie Formation (Es3) of the Gaoshangpu structural belt in the Nanpu Sag, is studied by high-pressure mercury injection, nuclear magnetic resonance, and constant-rate-controlled mercury porosimetry. The results show that the Es3 reservoir can be divided into three types: the pore radii of Type I reservoirs range from 120 to 180 µm, and the throat radii are larger than 1 µm, resulting in good pore connectivity; pore radii of Type II reservoirs are approximately 100 µm, and the throat radii range from 0.1 to 1 µm, resulting in moderate pore connectivity; and pore radii of Type III reservoirs are much smaller than 100 µm, and the throat radii are smaller than 0.1 µm, resulting in worst pore connectivity. The pore size of Type I reservoirs is most sensitive to compaction, and the pore connectivity is mainly controlled by carbonate cementation; the pore throat size and pore connectivity of Type II reservoirs are seriously affected by clay cementation, and pores are mainly formed by dissolution. However, the pore structure of Type III reservoirs is the worst among those investigated in this study but can be further improved by dissolution to a certain extent. Volcanic activity controls cementation and affects dissolution, thus changing the pore structure. A pore structure evolution model is established, which can provide a reference for future oil gas exploration.

Repetitive brief ischemia accelerates tibial shaft fracture healing: a 5-years prospective preliminary clinical trial (PCT).

BACKGROUND: This study was to evaluate the effects of repetitive brief ischemia (RBI) on bone healing in patients with tibial shaft fractures. METHODS: In this prospective clinical trial, patients with tibia shaft fractures were enrolled between January 2016 and January 2021. The intermittent pneumatic compression (IPC) device was used to make RBI on the affected limb after surgical operation 24 h. The inflation pressure was the systolic pressure of patients + 50 mmHg. Patients were received 30 s inflation/30 s deflation 30 times twice a day for 4 weeks. The primary outcome was bone healing time and the secondary outcomes were the rates of delayed union and nonunion, the rates of venous thrombosis of lower limbs, Johner-Wruhs scores, Lysholm knee score, VAS scores, postoperative complications, serum BMP-2, osteocalcin (OC) and bone specific alkaline phosphatase (BS-ALP). RESULTS: A total of 32 patients were enrolled finally and all were completed with a 12 months follow-up. All the fractures were healed and the bone healing time was 3(1) months in RBI group. However, the bone healing time of control group was 4(1) and there was statistical difference between the two groups (p < 0.01). No patient with fracture delayed union, nonunion and venous thrombosis of lower limbs in RBI group. 2 patients were delayed union in the control group. In RBI group, the Lysholm knee score was 83(6) at 6 months and 100(8) at 12 months. In the control group, the score was 78(4) and 90.5(17), there was statistical difference between the two groups (p < 0.01, p = 0.014, respectively). VAS scores were postoperative 2 weeks 6(1) in RBI group and 7(0.5) in the control group, there was statistical difference between the two groups (p = 0.016). There were 2 patients with intramuscular venous thrombosis of lower extremity in control group. Besides, RBI treatment increased the serum BMP-2, OC and BS-ALP at postoperative 2 weeks and 1 month. CONCLUSIONS: RBI is a new method to accelerate bone healing in tibia shaft fracture patients and is a simple and noninvasive method. TRIAL REGISTRATION: Chinese clinical trial registry, ChiCTR-INR-17014208 . Registered 28 December 2017-Retrospectively registered.

Synthesis, Structure, and Catalytic Hydrogenation Activity of [NO]-Chelate Half-Sandwich Iridium Complexes with Schiff Base Ligands.

A series of N,O-coordinate iridium(III) complexes with a half-sandwich motif bearing Schiff base ligands for catalytic hydrogenation of nitro and carbonyl substrates have been synthesized. All iridium complexes showed efficient catalytic activity for the hydrogenation of ketones, aldehydes, and nitro-containing compounds using clean H2 as reducing reagent. The iridium catalyst displayed the highest TON values of 960 and 950 in the hydrogenation of carbonyl and nitro substrates, respectively. Various types of substrates with different substituted groups afforded corresponding products in excellent yields. All N,O-coordinate iridium(III) complexes 1-4 were well characterized by IR, NMR, HRMS, and elemental analysis. The molecular structure of complex 1 was further characterized by single-crystal X-ray determination.

Cyclometalated Half-Sandwich Iridium(III) Complexes: Synthesis, Structure, and Diverse Catalytic Activity in Imine Synthesis Using Air as the Oxidant.

Four air-stable cyclometalated half-sandwich iridium complexes 1-4 with C,N-donor Schiff base ligands were prepared through C-H activation in moderate-to-good yields. These complexes have been well characterized, and their exact structure was elaborated on by single-crystal X-ray analysis. The iridium(III) complexes 1-4 showed good catalytic activity in the imine synthesis under open-flask conditions (air as the oxidant) from primary amine oxidative homocoupling, secondary amine dehydrogenation, and the cross-coupling reaction of amine and alcohol. Substituents bonded on the ligands of the iridium complexes displayed little effect on the catalytic efficiency. The stability and good catalytic efficiency of the iridium catalysts, mild reaction conditions, and substrate universality showed their potential application in industrial production.

Role of carbonyl sulfide in acute lung injury following limb ischemia/reperfusion in rats.

OBJECTIVE: To investigate the effect of carbonyl sulfide (COS) on limb ischemia/reperfusion (I/R)-induced acute lung injury (ALI) and the associated mechanism in rats. METHODS: ALI was induced by bilateral hind limb I/R in Sprague-Dawley (SD) rats. Sixty-four SD rats were randomly divided into the control group, I/R group, I/R + COS group, and I/R + AIR group. We observed the survival rate of the rats and the morphological changes of lung tissues, and we measured the change in the lung coefficient, the expression levels of the intercellular adhesion factor-1 (ICAM-1) protein in lung tissue, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-lß, and interleukin (IL)-6 in both lung tissue and serum, and cell apoptosis. RESULTS: Limb I/R caused significant lung tissue damage. The number of polymorphonuclear neutrophil in alveolar septa, the expression level of the ICAM-1 protein in lung tissue, the expression levels of TNF-α, IL-1, and IL-6 in lung tissue and serum, the lung coefficient, and cell apoptosis all increased. When a low dose of COS gas was administered prior to limb I/R, the variation of the above indicators was significantly reduced, while an increase in the dose of COS did not reduce the lung injury but rather increased the mortality rate. CONCLUSION: Carbonyl sulfide is another new gaseous signaling molecule, and a low dose of exogenous COS may play a protective role in I/R-induced ALI by acting as an anti-inflammatory agent by promoting the production of antioxidants and by inhibiting the expression of adhesion molecule proteins.