The efficacy and safety of tranexamic acid for reducing blood loss following simultaneous bilateral total knee arthroplasty: a multicenter retrospective study

Background

The purpose of the study was to evaluate whether tranexamic acid (TXA) administration could reduce blood loss and transfusion risk after simultaneous bilateral total knee arthroplasty (SBTKA).

Methods

As a multicenter retrospective study, a total of 575 patients were assigned into three groups on the basis of TXA usage, including intravenous (IV) group (1 g IV TXA 5–10 min prior to the incision), combined group (1 g IV TXA combined with intra-articular injection of 1 g TXA prior to the closure every knee) and control group (no TXA use). The primary outcomes were total blood loss (TBL). The secondary outcomes were maximum hemoglobin (Hb) and hematocrit (Hct) drop, transfusion rate, drain volume, length of stay, hospitalization expenses and the incidence of complications.

Results

The mean TBL in control group (1685.0 ± 571.4 mL) were higher than that in IV group (1061.1 ± 689.6 mL, p = 0.006 and combined group (988.3 ± 559.3 mL, p = 0.003). The maximum Hb and Hct drop in combined group (28.5 ± 13.4 g/L, p = 0.016; 0.074 ± 0.053, p < 0.001) and IV group (28.8 ± 14.5 g/L, p = 0.025; 0.082 ± 0.056, p = 0.001) were lower than those in control group (33.4 ± 14.0; 0.131 ± 0.049). But the difference between IV and combined groups was not significant. The similar trend was detected on drain volume, length of stay and hospitalization expenses. The incidence of complications did not differ significantly among the three groups (p > 0.05).

Conclusions

The study indicates that TXA could reduce blood loss with no apparent increase in the incidence of complications during SBTKA.

A nested case-control study on the risk factors of deep vein thrombosis for Chinese after total joint arthroplasty

Background

Deep vein thrombosis (DVT) is one of the life-threatening complications of total joint arthroplasty (TJA) postoperatively, and its risk factors are still controversial. The aim of this study was to identify the risk factors of DVT after TJA.

Study design and methods

A nested case-control study based on a large dataset of 15,326 patients undergoing TJA was performed. Potential risk factors of DVT and demographic information were extracted from the electronic health record. Patients with DVT (73 patients) were treated as study group while non-DVT patients who were matched 1:4 according to the anticoagulant type, were considered as control group (292 patients). These variables of potential risk factors for DVT including age, sex, body mass index (BMI), American Society of Anesthesiologists class, comorbidity, preoperative hemoglobin (HB) level and analgesic use, surgical site (knee or hip) and type, the start time of drug anticoagulation, ambulation time, transfusion, and whether to use tranexamic acid (TXA), drain, human serum albumin, and measures of physical thromboprophylaxis after operation were collected and evaluated by survival analysis and presented as P value and odds ratio with 95% confidence interval.

Results

There were 15,326 patients underwent TJA and 73 (0.48%) patients had DVT among them, and the occurrence rates were 0.71% for the patients underwent total knee arthroplasty (TKA) while 0.24% for total hip arthroplasty. The risk factors associated with DVT included TKA (compared with THA), advanced age (> 70 years), drain use, and delayed ambulation (≥ 72 h) postoperatively.

Conclusion

The present results suggest that the occurrence rate of DVT on the patients underwent TJA was low (0.48%) relatively. And the risk factors associated with increased risk of DVT included TKA (compared with THA), advanced age, drain use, and delayed ambulation postoperatively. Individualized and more efficient risk stratification protocols of anticoagulation after TJA for Chinese may need to be developed in the future.

Direct Detection of Dimer Orbitals in Ba_{5}AlIr_{2}O_{11}

The electronic states of many Mott insulators, including iridates, are often conceptualized in terms of localized atomic states such as the famous "J_{eff}=1/2 state." Although orbital hybridization can strongly modify such states and dramatically change the electronic properties of materials, probing this process is highly challenging. In this Letter, we directly detect and quantify the formation of dimer orbitals in an iridate material Ba_{5}AlIr_{2}O_{11} using resonant inelastic x-ray scattering. Sharp peaks corresponding to the excitations of dimer orbitals are observed and analyzed by a combination of density functional theory calculations and theoretical simulations based on an Ir-Ir cluster model. Such partially delocalized dimer states lead to a redefinition of the angular momentum of the electrons and changes in the magnetic and electronic behaviors of the material. We use this to explain the reduction of the observed magnetic moment with respect to predictions based on atomic states. This study opens new directions to study dimerization in a large family of materials, including solids, heterostructures, molecules, and transient states.

Total hospital cost, length of stay, and complications between simultaneous and staged bilateral total hip arthroplasty: A nationwide retrospective cohort study in China

This retrospective cohort study aimed to compare the total hospital cost, length of stay (LOS), and incidence of complications between simultaneous bilateral total hip arthroplasty (simBTHA) and staged bilateral total hip arthroplasty (staBTHA).We identified 256 patients who underwent staBTHA and matched them to a control group of 256 patients who underwent simBTHA from 2013 to 2016. Patients' demographics, total hospital costs, complication rates, and LOS were recorded and compared.Patients undergoing simBTHA were younger (52.0 ± 12.0 vs 54.9 ± 13.2 years, P = .01), were more likely to be men (55.9% vs 46.9%, P = .04). There was no significant difference in total hospital costs or complications within 90 days for simBTHA compared with staBTHA. The transfusion rate was higher (49.3% vs 10.4%, P < .01), but the LOS was shorter in the simBTHA group (8.7 ± 5.3 vs 12.1 ± 5.6 days, P < .01).There were no differences in total hospital costs or complications within 90 days if patients were carefully selected for simBTHA. Considering the difference in baseline characteristics and the low level of evidence, further randomized controlled studies are necessary.

Multiple Doses of Perioperative Dexamethasone Further Improve Clinical Outcomes After Total Knee Arthroplasty: A Prospective, Randomized, Controlled Study

BACKGROUND

This study aimed to evaluate the effect and safety of multiple doses of preoperative dexamethasone on pain and recovery after total knee arthroplasty (TKA).

METHODS

Altogether, 182 patients undergoing TKA received 3 intravenous injections of normal saline (group A), 1 injection of high-dose dexamethasone (20 mg) and 2 injections of normal saline (group B), or 1 injection of high-dose dexamethasone and 2 injections of low-dose (10 mg) dexamethasone (group C).

RESULTS

Visual analog scale was lower in group C than in group A or B and was different between groups A and B on postoperative days 1, 2, and 3 (all P < .05). Fewer group C patients required analgesic rescue and had lower total analgesic than those in group A or B, with the same difference between groups A and B (all P < .05). C-reactive protein and interleukin-6 levels were lower in groups B and C than in group A at 24, 48, and 72 hours postoperatively. C-reactive protein at 72 hours and interleukin-6 at 48 and 72 hours were lower in group C than in group B (all P < .05). Incidences of postoperative nausea and vomiting, number of patients requiring antiemetic rescue, and overall consumption of metoclopramide were lower in groups B and C than in group A (all P < .05). No surgical-site infections or gastrointestinal hemorrhages were detected in any group.

CONCLUSION

Multiple dexamethasone doses further reduced postoperative pain, decreased consumption of analgesic drugs, and provided more powered inflammation control. These findings call for further studies to further evaluate its safety.

Efficacy and safety of multiple boluses of oral versus intravenous tranexamic acid at reducing blood loss after primary total knee arthroplasty without a tourniquet: A prospective randomized clinical trial

INTRODUCTION

The aim of this study was to examine whether the administration of multiple boluses of oral or intravenous tranexamic acid (TXA) postoperatively were equivalent at reducing blood loss and the inflammatory and fibrinolytic responses in primary total knee arthroplasty (TKA) without a tourniquet.

MATERIALS AND METHODS

In this prospective, double-blinded, randomized trial, patients undergoing primary THA were randomized into either an oral or intravenous TXA group. All patients received 1 dose of 20 mg/kg intravenous TXA 5-10 min before skin incision. Patients in the oral TXA group then received 3 doses of 2 g oral TXA at 4, 10, and 16 h postoperatively, while patients in the intravenous TXA group received 3 doses of 1 g intravenous TXA at 6, 12, and 18 h after surgery.

RESULTS

There was no significant difference in the hemoglobin (Hb) or hematocrit (Hct) drop on postoperative day 1 (14.7 ± 10.5 vs 14.4 ± 9.6 g/L, p = 0.869; 0.042 ± 0.032 vs 0.040 ± 0.028, p = 0.781) and 3 (22.6 ± 10.6 vs 20.5 ± 9.7 g/L, p = 0.300; 0.059 ± 0.031 vs 0.054 ± 0.031, p = 0.332). No patients needed an allogeneic blood transfusion. The mean total blood loss, hidden blood loss, length of hospital stay, the level of inflammatory and fibrinolytic markers on the first and third postoperative days, and the incidence of complications were not significantly different between the two groups (p > 0.05).

CONCLUSION

There was no difference in Hb and Hct drop, blood loss, inflammatory and fibrinolytic responses in primary TKA without a tourniquet between those who received multiple boluses of oral or intravenous TXA after surgery in current scheme.

[Risk factors associated with interleukin 6 level in serum after total knee arthroplasty]

Objective

To explore the risk factors associated with interleukin 6 (IL-6) level in serum after total knee arthroplasty (TKA).

Methods

A retrospective study was made on the clinical data of 273 patients underwent primary unilateral TKA between July 2015 and April 2017. There were 50 males and 223 females with an average age of 66.3 years (range, 36-89 years), and the body mass index (BMI) was (25.5±3.7) kg/m ². Of them, 256 patients suffered with osteoarthritis, and the other 17 patients with rheumatoid arthritis. Univariate analysis was made to find the related factors between IL-6 level in serum at 1 day after operation and preoperative data including gender, age, BMI, diagnosis, comorbidities, preoperative American Society of Anesthesiologists (ASA) grade, preoperative varus or valgus deformity, range of motion of the knee, preoperative level of C-reactive protein (CRP) and IL-6 in serum, operation time, intraoperative blood loss, usage of drainage tube and catheter, and dosage of tranexamic acid and dexamethasone used on day of operation. Furthermore, the multiple linear regression analysis was performed to identify the risk factors.

Results

The operation time was (79.7±15.6) minutes, and the intraoperative blood loss was (107.8±25.3) mL. Drainage tubes were used in 111 patients and catheters were used in 41 patients after operation. The dosage of tranexamic acid and dexamethasone used on day of operation were (3.2±0.8) g and (15.1±6.6) mg, respectively. The levels of IL-6 in serum were (4.48±3.05), (42.65±37.09), and (28.21±26.44) pg/mL before operation and at 1 and 3 days after operation, respectively. Univariate analysis showed that the level of IL-6 in serum at 1 day after operation was significantly higher in variables as follows: age, diagnosis, history of lung infection, range of motion, preoperative levels of CRP and IL-6 in serum, intravenous dosage of tranexamic acid and dexamethasone on day of operation ( P<0.05). Multiple linear regression analysis showed that range of motion less than 90°, intravenous dosage of tranexamic acid on day of operation less than 3 g, and dosage of dexamethasone on day of operation less than 10 mg were significant risk factors ( P<0.05).

Conclusion

Range of motion less than 90°, intravenous dosage of tranexamic acid on day of operation less than 3 g, and dosage of dexamethasone on day of operation less than 10 mg were independent risk factors that resulted in increased level of IL-6 in serum at 1 day after TKA.

Signals in Stem Cell Differentiation on Fluorapatite-Modified Scaffolds

Previously, we reported that the fluorapatite (FA)-modified polycaprolactone (PCL) nanofiber could be an odontogenic/osteogenic inductive tissue-engineering scaffold by inducing stem cell differentiation and mineralization. The present study aimed to explore which of the signal pathways affected this differentiation and mineralization process. The Human Signal Transduction PathwayFinder RT² Profiler PCR Array was used to analyze the involvement of potential signal transduction pathways during human dental pulp stem cell (DPSCs) osteogenic differentiation induced by FA-modified PCL nanofiber scaffolds. Based on the results, perturbation studies of the signaling pathways hedgehog, insulin, and Wnt were performed. Moreover, the autophagy process was studied, as indicated by the expression of the microtubule-associated protein 1 light chain 3A/B-II (LC3-II) and the cell osteogenic phenotypic changes. In a comparison of the cells grown on PCL + FA scaffolds and those on PCL-only scaffolds, the transcript expression of BMP2, BMP4, FOXA2, PTCH1, WNT1, and WNT2 (PCR array-labeled signal proteins of the hedgehog pathway); CEBPB, FASN, and HK2 (PCR array-labeled signal proteins of the insulin pathway); and CCND1, JUN, MYC, TCF7, and WISP1 (PCR array-labeled signal proteins of the Wnt pathway) doubled at day 14 when obvious cell osteogenic differentiation occurred. Phenotypically, in all the perturbation groups at day 14, ALP activity, OPN, and autophagy marker LC3-II expression were coincidently decreased. Consistently, no positive alizarin red staining or von Kossa staining was observed in the specimens from these perturbation groups at day 28. The results showed that when obvious cell differentiation occurred at day 14 on PCL + FA control groups, the inhibition of the hedgehog, insulin, and Wnt pathways significantly decreased DPSC osteogenic differentiation and mineralization. The osteogenic differentiation of DPSCs grown on FA-modified PCL scaffolds appeared to be positively modulated by the hedgehog, insulin, and Wnt signal pathways, which were coordinated with and/or mediated by the cell autophagy process.

Incidence and Risk Factors for Blood Transfusion in Simultaneous Bilateral Total Joint Arthroplasty: A Multicenter Retrospective Study

BACKGROUND

The aim of this study was to identify the incidence and risk factors for blood transfusion in patients undergoing simultaneous bilateral total hip arthroplasty (SBTHA) and simultaneous bilateral total knee arthroplasty (SBTKA).

METHODS

We identified 414 SBTHA and 1147 SBTKA procedures, and separated the patients into those who did and did not require allogeneic blood transfusion. A multivariate logistic regression model was used to identify independent risk factors for transfusion.

RESULTS

The transfusion rate after SBTHA was 50.0%, and significant risk factors for transfusion were female gender (odds ratio [OR] = 2.612), lower body mass index (OR = 1.093), inflammatory arthritis (OR = 1.970), American Society of Anesthesiologists (ASA) class ≥3 (OR = 3.477), drain use (OR = 4.607), and increased intraoperative bleeding. We also found that higher preoperative hemoglobin (Hb) and tranexamic acid use decreased the risk of transfusion. The transfusion rate after SBTKA was 29.1%, and significant risk factors for transfusion were ASA class ≥3 (OR = 8.959), tourniquet use (OR = 2.129), drain use (OR = 4.970), and increased intraoperative bleeding. A higher preoperative Hb was the only protective factor for transfusion.

CONCLUSION

For SBTHA, the risk factors included female gender, lower body mass index, inflammatory arthritis, ASA class ≥3, drain use, and increased intraoperative bleeding, while for SBTKA, risk factors were ASA class ≥3, tourniquet use, drain use, and increased intraoperative bleeding. Increasing the preoperative Hb level may decrease transfusion risk. In addition, tranexamic acid was encouraged to use to decrease transfusion need in SBTHA.

[Clinical research on perioperative restrictive fluid therapy combined with preoperative urination training in total hip arthroplasty]

Objective

To evaluate the effectiveness and safety of restrictive fluid therapy combined with preoperative urination training during perioperative period in an enhanced recovery after surgery (ERAS) program for primary total hip arthroplasty (THA).

Methods

A retrospective study were conducted in 73 patients who underwent unilateral THA with liberal intravenous fluid therapy on the day of surgery between April 2015 and March 2016 (control group) and in 70 patients with restrictive fluid therapy and preoperative urination training between November 2016 and April 2017 (trial group). There was no significant difference in gender, age, weight, height, body mass index, primary disease, and complications between 2 groups ( P>0.05). Perioperative related indexes were recorded and compared between 2 groups, including operation time; pre-, intra-, post-operative intravenous fluid volumes, overall intravenous fluid volume on the surgery day; postoperative urine volume per hour after surgery; blood volume; total blood loss during perioperative period; usage rates of diuretics and urine tube; the incidences of hypotension, nausea and vomiting, hyponatremia, and hypokalemia after surgery; postoperative length of stay; and the expressions of inflammatory factors [C reaction protein (CRP), interleukin-6 (IL-6)] before sugery and at 1st and 2nd days after surgery.

Results

The pre-, intra-, post-operative intravenous fluid volumes and the overall intravenous fluid volume on the surgery day in trial group were significantly lower than those in control group ( P<0.05). There was no significant difference in operation time, blood volume, total blood loss during perioperative period, and postoperative urine volume per hour after surgery between 2 groups ( P>0.05). The usage rates of diuretics and urine tube in trial group were significantly lower than those in control group ( P<0.05), while the differences in incidences of hypotension, nausea and vomiting, hyponatremia, and hypokalemia after surgery of 2 groups were insignificant ( P>0.05). The level of inflammation factors (CRP, IL-6) at 1st and 2nd days was significant lower in trial group than in control group ( P<0.05), with shorter postoperative length of stay ( t=-5.529, P=0.000).

Conclusion

It is safe and effective to adopt restrictive fluid therapy and preoperative urination training during perioperative period (intravenous fluid volume controls in about 1 200 mL on the day of surgery) following ERAS in primary THA. However, prospective studies with large-scale are still in demand for further confirming the conclusion.

Decoupling of magnetism and electric transport in single-crystal (Sr1-x A x )2IrO4 (A = Ca or Ba)

We report a systematical structural, transport and magnetic study of Ca or Ba doped Sr₂IrO₄ single crystals. Isoelectronically substituting Ca²⁺ (up to 15%) or Ba²⁺ (up to 4%) ion for the Sr²⁺ ion provides no additional charge carriers but effectively changes the lattice parameters in Sr₂IrO₄. In particular, 15% Ca doping considerably reduces the c-axis and the unit cell by nearly 0.45% and 1.00%, respectively. These significant, anisotropic compressions in the lattice parameters conspicuously cause no change in the Néel temperature which remains at 240 K, but drastically reduces the electrical resistivity by up to five orders of magnitude or even precipitates a sharp insulator-to-metal transition at lower temperatures, i.e. the vanishing insulating state accompanies an unchanged Néel temperature in (Sr_1-x A _x )₂IrO₄. This observation brings to light an intriguing difference between chemical pressure and applied pressure, the latter of which does suppress the long-range magnetic order in Sr₂IrO₄. This difference reveals the importance of the Ir1-O2-Ir1 bond angle and homogenous volume compression in determining the magnetic ground state. All results, along with a comparison drawn with results of Tb and La doped Sr₂IrO₄, underscore that the magnetic transition plays a nonessential role in the formation of the charge gap in the spin-orbit-tuned iridate.

Multiple Low-Dose Dexamethasone Further Improves Clinical Outcomes Following Total Hip Arthroplasty

BACKGROUND

The recommended dose regimen of dexamethasone in total hip arthroplasty (THA) has not been determined. This study was performed to assess the effects of multiple low-dose dexamethasone on clinical outcomes after THA.

METHODS

Two hundred ten patients undergoing THA received 3 doses of normal saline (Group A), 2 doses of intravenous dexamethasone and 1 dose of normal saline (Group B), or 3 doses of intravenous dexamethasone (Group C). The primary outcome was the visual analog scale (VAS) score for pain and nausea. The incidence of postoperative nausea and vomiting, use of analgesic and antiemetic rescue, C-reactive protein (CRP) level, range of motion, length of stay (LOS), and complications were also compared.

RESULTS

The VAS score (dynamic pain and nausea) on postoperative day 1 was significantly lower in Groups C and B than Group A. On postoperative day 2, the VAS score (dynamic pain and nausea) was lower in Group C than Groups A and B. In Group C, patients had a lower incidence of postoperative nausea and vomiting and reduced use of analgesic and antiemetic rescue. The CRP level was lower in Group B than Group A. Group C had the lowest CRP level among all 3 groups. LOS was shorter in Group B than Group A, while Group C had an even shorter LOS than Group B. Range of motion was greater in Group C. No complications occurred in any group.

CONCLUSION

The 3-dose dexamethasone regimen can further relieve postoperative pain, ameliorate postoperative nausea, provide additional inflammatory control, enhance mobility, and shorten LOS following THA.

Gait Analysis of Leg Length Discrepancy-Differentiated Hip Replacement Patients With Developmental Dysplasia: A Midterm Follow-Up

BACKGROUND

Few studies investigate gait characteristics and symmetry of developmental dysplasia of the hip patients (Crowe II and III) after total hip arthroplasty (THA) whose leg length discrepancy (LLD) is within 20 mm. Our study aimed to explore whether gait analysis parameters in these patients can return to the level of unaffected people and how bodies compensate for the discrepancy.

METHOD

A total of 45 patients who underwent cementless THA and 20 healthy controls were involved in this study prospectively. Group 1 includes patients whose LLD is <10 mm and group 2 includes patients whose LLD is 10-20 mm. Gait analysis was performed during 5-year midterm postoperative follow-up.

RESULT

The parameters, particularly the range of motion (ROM) in the hip, in both experimental groups (1 and 2) were significantly lower than healthy control group. For the nonoperated side, group 1 displayed significantly reduced ROM in the hip and knee compared with the age-matched controls. This was not observed in group 2. Greater bilateral symmetry can be seen in group 1 compared with group 2.

CONCLUSION

Despite LLD being limited to within 20 mm, THA patients in both groups showed a less efficient gait than that of healthy controls on 5-year midterm follow-up. The increased ROM in the nonoperated hip may act as a compensatory mechanism. LLD of 10 mm may be a cutoff value to assess whether compensation occurs in the contralateral limb. Reconstruction of equal limb length is recommended when surgeons perform THA for dysplastic hips.

The efficacy and safety of multiple-dose oral tranexamic acid on blood loss following total hip arthroplasty: a randomized controlled trial

PURPOSES

To explore the efficacy and safety of multiple-dose oral tranexamic acid (TXA) on blood loss following primary total hip arthroplasty (THA).

METHODS

A total of 152 patients were randomized into three groups to receive 2 g of oral TXA two hours  pre-operatively (group A), or another bolus of 2 g of oral TXA four hours post-operatively (group B), or another three boluses of 2 g of oral TXA four, ten, and 16 hours post-operatively (group C). The primary outcomes were total blood loss (TBL), hidden blood loss (HBL), and transfusion rate. The secondary outcomes were haemoglobin (Hb) and haematocrit (Hct) drop, the level of fibrinolysis parameters (fibrin degradation products, D-dimer), and complications (thrombotic diseases, stroke, cardiac infarction, and infection).

RESULTS

The mean TBL and HBL in group C were lower than those in group A (p < 0.001 and p < 0.001) and group B (p = 0.012 and p = 0.029). The Hb drop on post-operative day one (POD1) and POD3 in group C was lower than those in group A (p < 0.001 and p = 0.029) and group B (p < 0.001 and p = 0.004). The difference was similar regarding Hct drop on POD3 (p < 0.001 and p = 0.014). Moreover, fibrin degradation products and D-dimer in group C were lower than in groups A and B on POD1 and POD3 (p < 0.001 and p < 0.001). The incidence of complications such as venous thromboembolism did not differ significantly among the three groups (p > 0.05).

CONCLUSIONS

Multiple boluses of oral TXA could further reduce blood loss, Hb and Hct drop, and restrain post-operative fibrinolysis in primary THA without increasing the risk of complications.

LEVEL OF EVIDENCE I

Therapeutic study.

Molecular characterization and expression patterns of ghrelin in the reindeer (Rangifer tarandus)

Ghrelin is a novel growth hormone (GH)-releasing peptide, which has been identified as an endogenous ligand for the GH-sretagogue receptor. The sequence and expression of ghrelin has been determined in many species. In this study, to reveal the molecular characterization and expression patterns of ghrelin in the reindeer (Rangifer tarandus), the full-length DNA and cDNA encoding ghrelin were cloned from reindeer stomach using genome walking and rapid amplification of complementary deoxyribonucleic acid ends (RACE). The expression of ghrelin in almost all tissues was examined by real-time quantitative PCR (RT-qPCR). The 4076 bp amplicon of the ghrelin gene consisting of 4 exons and 3 introns was cloned from reindeer. Results of cDNA cloning and sequence analysis revealed that the full-length ghrelin cDNA was composed of 539 bp that included a 5'-untranslated region (46 bp), an open reading frame (ORF) (351 bp), and a 3'-untranslated region (142 bp). In addition, ghrelin was expressed in the all tissues examined, with the expression in the abomasum significantly higher than that in other tissues (p<0.05), followed by the pancreas, duodenum, testis and oesophagus. The results show that the expression of ghrelin in the reindeer gastrointestinal tract is extensive, suggesting its may have a role in regulating the digestive function.

The effect of oral versus intravenous tranexamic acid in reducing blood loss after primary total hip arthroplasty: A randomized clinical trial

BACKGROUND

The purpose of this study was to determine whether the administration of multiple boluses of oral and intravenous tranexamic acid (TXA) postoperatively was equivalent in reducing blood loss in primary THA.

METHODS

A total of 108 patients were randomized into two groups: oral TXA group (54 patients receiving 1 dose of 20 mg/kg intravenous TXA 5-10 min before skin incision and 3 doses of 2 g oral TXA 4 h, 10 h and 16 h postoperatively) and intravenous TXA group (54 patients receiving 1 dose of 20 mg/kg intravenous TXA 5-10 min before skin incision and 3 doses of 1 g intravenous TXA 6 h, 12 h and 18 h postoperatively). The primary outcomes were total blood loss, hidden blood loss, length of hospital stay, hemoglobin (Hb) and hematocrit (Hct) drop. The secondary outcomes were the level of inflammation markers and complications.

RESULTS

There was no difference in the mean total blood loss or hidden blood loss [728.4 (645.8-806.9) mL vs 703.6 (576.9-832.8) mL, p = 0.745; 634.6 (552.0-715.7) mL vs 606.4 (480.1-734.5) mL, p = 0.710] and length of hospital stay was similar between the two groups. No patients received allogenic blood transfusion. The Hb and Hct drop on the first and second postoperative days were similar (p > 0.05). The level of inflammation markers did not reach statistical significance. The incidence of complications did not differ significantly between the two groups.

CONCLUSIONS

Multiple boluses of oral TXA and intravenous TXA postoperatively are equivalent in reducing blood loss, Hb and Hct drop in primary THA without increasing the risk of thromboembolic diseases and wound complications.

Factors influencing postoperative length of stay in an enhanced recovery after surgery program for primary total knee arthroplasty

Background

Hospital length of stay (LOS) after primary total knee arthroplasty (TKA) has decreased obviously following the implementation of enhanced recovery after surgery (ERAS) program in the last few years. However, there are still some patients that cannot be discharged at early time for a variety of reasons, and it is necessary to explore factors leading to prolonged LOS. Therefore, the purpose of this study was to identify the complete preoperative, perioperative, and postoperative factors associated with prolonged postoperative LOS (PLOS) after primary TKA in a detailed ERAS program.

Methods

In a consecutive series from July 2015 to March 2017, all patients who underwent unilateral elective primary TKA were included in the retrospective study. A PLOS greater than 3 days was considered a prolonged PLOS. Multivariable logistic regression analysis was performed to identify patient characteristics and relevant preoperative, perioperative, and postoperative variables that were associated with prolonged PLOS and postoperative complications.

Results

A total of 241 patients were included with a mean PLOS of 3.8 days. Prolonged PLOS was significantly associated with preoperative valgus deformity of the knee (OR 4.95, 95%CI 1.56–15.77, P = 0.007), increased serum level of interleukin-6 on postoperative day 1 (OR 1.01, 95%CI 1.00–1.03, P = 0.039), increased visual analogue scale pain score and serum level of C-reactive protein on postoperative day 3 (OR 2.56, 95%CI 1.28–5.13, P = 0.008; OR 1.01, 95%CI 1.00–1.03, P = 0.019), increased day to achieve 90° active knee flexion after surgery (OR 2.19, 95%CI 1.27–3.79, P = 0.005), and postoperative wound complications (OR 8.58, 95%CI 2.10–35.03, P = 0.003) and other minor complications (OR 6.04, 95%CI 2.40–15.19, P < 0.001). Preoperative pulmonary infection (OR 2.75, 95%CI 1.20–6.28, P = 0.016), American Society of Anesthesiologists score 3/4 (OR 2.14, 95%CI 1.01–4.52, P = 0.046), and utilization of catheter after surgery (OR 2.53, 95%CI 1.23–5.19, P = 0.012) were significantly associated with postoperative complications.

Conclusions

Multiple factors were associated with prolonged PLOS and postoperative complications after TKA in the ERAS program. It is important to recognize all the factors to try to maximize the use of medical resources and ultimately optimize the care of our patients.

Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr_{2}IrO_{4}

Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic Mott state is sufficient to attain that goal. The antiferromagnetic insulator Sr_{2}IrO_{4} provides a model system in which strong SOI lock canted Ir magnetic moments to IrO_{6} octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the Néel temperature and drives a large, nonlinear lattice expansion that closely tracks the magnetization, increases the electron mobility, and precipitates a unique resistive switching effect. Our observations open new avenues for understanding fundamental physics driven by strong SOI in condensed matter, and provide a new paradigm for functional materials and devices.

Effectiveness and safety of an optimized blood management program in total hip and knee arthroplasty: A large, single-center, retrospective study

Little has been published on blood management in total hip and knee arthroplasty (THA and TKA, respectively) patients focusing on both hematopoiesis and hemostasis. Our aim was to explore the effectiveness and safety of an optimized blood management program in THA and TKA patients in a large, single-center, retrospective study.We retrospectively reviewed consecutive primary unilateral THA and TKA patients' data at our institution through the National Health Database. They were divided into 3 groups according to an optimized blood management program: group A-combined use of intravenous and topical tranexamic acid (TXA); group B-use of recombinant human erythropoietin (rHuEPO) and iron supplements in addition to treatments in group A; group C-use of additional multiple boluses of TXA in addition to treatments in group B. The primary outcomes were hemoglobin (Hb) drop and calculated total blood loss (TBL). Other outcome measurements such as transfusion rate, postoperative length of stay (PLOS), venous thromboembolism (VTE), and mortality were also compared.From 2014 to 2016, a total of 1907 unilateral THA (986 in group A, 745 in group B, and 176 in group C) and 1505 unilateral TKA (795 in group A, 556 in group B, and 154 in group C) procedures were conducted at our institution. The Hb drop, calculated TBL, and PLOS in group C were significantly lower than those in groups A and B for THA and TKA patients. The transfusion rate in group C was also significantly less than in groups A and B for THA patients, while it was similar in groups A and B for TKA patients. No patients in group C received a transfusion. A significant difference was not detected in the incidence of deep vein thrombosis. No episode of symptomatic pulmonary embolism or all-cause mortality occurred within 30 days postoperatively.The current retrospective study suggests that for patients receiving primary unilateral THA or TKA, multiple boluses of intravenous TXA combined with topical TXA, rHuEPO, and iron supplements can reduce the calculated TBL, Hb drop, transfusion rate, and PLOS without increasing the incidence of VTE or mortality.

The Anti-Inflammatory Effect and Structure of EPCP1-2 from Crypthecodinium cohnii via Modulation of TLR4-NF-κB Pathways in LPS-Induced RAW 264.7 Cells

Exopolysaccharide from Crypthecodinium cohnii (EPCP1-2) is a marine exopolysaccharide that evidences a variety of biological activities. We isolated a neutral polysaccharide from the fermentation liquid of Crypthecodinium cohnii (CP). In this study, a polysaccharide that is derived from Crypthecodinium cohnii were analyzed and its anti-inflammatory effect was evaluated on protein expression of toll-like receptor 4 and nuclear factor κB pathways in macrophages. The structural characteristics of EPCP1-2 were characterized by GC (gas chromatography) and GC-MS (gas Chromatography-Mass Spectrometer) analyses. The molecular weight was about 82.5 kDa. The main chain of EPCP1-2 consisted of (1→6)-linked mannopyranosyl, (1→6)-linked glucopyranosyl, branched-chain consisted of (1→3,6)-linked galactopyranosyl and terminal consisted of t-l-Rhapyranosyl. The in vitro anti-inflammatory activity was representated through assay of proliferation rate, pro-inflammatory factor (NO) and expressions of proteins on RAW 264.7, the macrophage cell line. The results revealed that EPCP1-2 exhibited significant anti-inflammatory activity by regulating the expression of toll-like receptor 4, mitogen-activated protein kinases, and Nuclear Factor-κB protein.

Left ventricular hypertrophy does not prevent heart failure in experimental hypertension

BACKGROUND

Left ventricular hypertrophy (LVH) secondary to hypertension has been accepted to prevent heart failure (HF) while paradoxically increasing cardiovascular morbi-mortality.

OBJECTIVES

To evaluate whether antihypertensive treatment inhibits LVH, restores beta-adrenergic response and affects myocardial oxidative metabolism.

METHODS

Ninety spontaneously hypertensive rats (SHR) were distributed into groups and treated (mg/kg, p.o.) with: losartan 30 (L), hydralazine 11 (H), rosuvastatin 10 (R), carvedilol 20 (C). Hypertension control group comprised 18 normotensive rats (Wistar-Kyoto, WKY). Following euthanasia at 16months, contractility was measured in 50% of rats (Langendorff system) before and after isoproterenol (Iso) 10^-9M, 10^-7M and 10^-5M stimulation. Left ventricular weight (LVW) was measured in the remaining hearts, and normalized by BW. Expression of thioredoxin 1 (Trx-1), peroxyredoxin 2 (Prx-2), glutaredoxin 3 (Grx-3), caspase-3 and brain natriuretic peptide (BNP) was determined.

RESULTS

Systolic blood pressure (mmHg): 154±3 (L), 137±1 (H), 190±3 (R)*, 206±3 (SHR)*, 183±1 (C)**, and 141±1 (WKY) (*p<0.05 vs. L, H, WKY, **p<0.05 vs. L, H, WKY, SHR). LVW/BW was higher in SHR and R (p<0.05). Groups SHR, R and C evidenced baseline contractile depression. Response to Iso 10^-5M was similar in WKY and L. Expression of Trx-1, Prx-2 and Grx-3 increased in C, H, R and L (p<0.01).

CONCLUSIONS

Present findings argue against the traditional idea and support that LVH might not be required to prevent HF. Increased expression of thioredoxins by antihypertensive treatment might be involved in protection from HF.

Dark Matter Search Results from the PICO-60 C_{3}F_{8} Bubble Chamber

New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41}  cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.

Doping Evolution of Magnetic Order and Magnetic Excitations in (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7}

We use resonant elastic and inelastic x-ray scattering at the Ir-L_{3} edge to study the doping-dependent magnetic order, magnetic excitations, and spin-orbit excitons in the electron-doped bilayer iridate (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} (0≤x≤0.065). With increasing doping x, the three-dimensional long range antiferromagnetic order is gradually suppressed and evolves into a three-dimensional short range order across the insulator-to-metal transition from x=0 to 0.05, followed by a transition to two-dimensional short range order between x=0.05 and 0.065. Because of the interactions between the J_{eff}=1/2 pseudospins and the emergent itinerant electrons, magnetic excitations undergo damping, anisotropic softening, and gap collapse, accompanied by weakly doping-dependent spin-orbit excitons. Therefore, we conclude that electron doping suppresses the magnetic anisotropy and interlayer couplings and drives (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} into a correlated metallic state with two-dimensional short range antiferromagnetic order. Strong antiferromagnetic fluctuations of the J_{eff}=1/2 moments persist deep in this correlated metallic state, with the magnon gap strongly suppressed.

Cu(ii)/DM-Segphos catalyzed asymmetric 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylides

Cu(OTf)₂/DM-Segphos catalyzed asymmetric 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylides was studied. The spiropyrrolidinyl-benzoisothiazolines were obtained in high yields with up to >99 : 1 dr and 99% ee.

Ozonetherapy protects from in-stent coronary neointimal proliferation. Role of redoxins

BACKGROUND

In-stent restenosis and poor re-endothelization usually follow percutaneous transluminal coronary angioplasty, even using drug-eluting stents, due to inflammation and oxidative stress. Medical ozone has antioxidant and anti-inflammatory properties and has not been evaluated in this context.

OBJECTIVES

To evaluate whether ozonotherapy might reduce restenosis following bare metal stents implantation in relation to the redoxin system in pigs.

METHODS

Twelve male Landrace pigs (51±9kg) underwent percutaneous transluminal circumflex coronary arteries bare metal stent implantation under heparine infusion and fluoroscopical guidance, using standard techniques. Pigs were randomized to ozonetherapy (n=6) or placebo (n=6) treatment. Before stenting (24h) and twice a week for 30days post-stenting, venous blood was collected, ozonized and reinfused. Same procedure was performed in placebo group except for ozonation. Both groups received antiplatelet treatment. Histopathology and immunohistochemistry studies were performed.

RESULTS

Severe inflammatory reaction and restenosis with increase in the immunohistochemical expression of thioredoxin-1 were observed in placebo group 30days after surgery. Oppositely, ozonetherapy drastically reduced inflammatory reaction and restenosis, and showed no increase in the Trx-1 immunohistochemical expression 30days after surgery. Immunolabeling for Prx-2 was negative in both groups. Ozonated autohemotherapy strikingly reduced restenosis 30days following PTCA with BMS implantation in pigs.

CONCLUSIONS

Stimulation of the redoxin system by ozone pretreatment might neutralize oxidative damage from the start and increase antioxidative buffering capacity post-injury, reducing further damage and so the demand for antioxidant enzymes. Our interpretation agrees with the ozone oxidative preconditioning mechanism, extensively investigated.

Investigations of metastable Ca2IrO4 epitaxial thin-films: systematic comparison with Sr2IrO4 and Ba2IrO4

We have synthesized thermodynamically metastable Ca2IrO4 thin-films on YAlO3 (110) substrates by pulsed laser deposition. The epitaxial Ca2IrO4 thin-films are of K2NiF4-type tetragonal structure. Transport and optical spectroscopy measurements indicate that the electronic structure of the Ca2IrO4 thin-films is similar to that of Jeff = 1/2 spin-orbit-coupled Mott insulator Sr2IrO4 and Ba2IrO4, with the exception of an increased gap energy. The gap increase is to be expected in Ca2IrO4 due to its increased octahedral rotation and tilting, which results in enhanced electron-correlation, U/W. Our results suggest that the epitaxial stabilization growth of metastable-phase thin-films can be used effectively for investigating layered iridates and various complex-oxide systems.

X-ray Absorption Spectroscopy Study of the Effect of Rh doping in Sr2IrO4

We investigate the effect of Rh doping in Sr2IrO4 using X-ray absorption spectroscopy (XAS). We observed appearance of new electron-addition states with increasing Rh concentration (x in Sr2Ir1-xRhxO4) in accordance with the concept of hole doping. The intensity of the hole-induced state is however weak, suggesting weakness of charge transfer (CT) effect and Mott insulating ground states. Also, Ir Jeff = 1/2 upper Hubbard band shifts to lower energy as x increases up to x = 0.23. Combined with optical spectroscopy, these results suggest a hybridisation-related mechanism, in which Rh doping can weaken the (Ir Jeff = 1/2)-(O 2p) orbital hybridisation in the in-planar Rh-O-Ir bond networks.

P53 functional abnormality in mesenchymal stem cells promotes osteosarcoma development

It has been shown that p53 has a critical role in the differentiation and functionality of various multipotent progenitor cells. P53 mutations can lead to genome instability and subsequent functional alterations and aberrant transformation of mesenchymal stem cells (MSCs). The significance of p53 in safeguarding our body from developing osteosarcoma (OS) is well recognized. During bone remodeling, p53 has a key role in negatively regulating key factors orchestrating the early stages of osteogenic differentiation of MSCs. Interestingly, changes in the p53 status can compromise bone homeostasis and affect the tumor microenvironment. This review aims to provide a unique opportunity to study the p53 function in MSCs and OS. In the context of loss of function of p53, we provide a model for two sources of OS: MSCs as progenitor cells of osteoblasts and bone tumor microenvironment components. Standing at the bone remodeling point of view, in this review we will first explain the determinant function of p53 in OS development. We will then summarize the role of p53 in monitoring MSC fidelity and in regulating MSC differentiation programs during osteogenesis. Finally, we will discuss the importance of loss of p53 function in tissue microenvironment. We expect that the information provided herein could lead to better understanding and treatment of OS.

Synthesis of 3,4,5-trisubstituted isoxazoles via 1,3-dipolar cycloaddition/SO2 extrusion of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrile oxides

An straightforward synthesis of 3,4,5-trisubstituted isoxazole derivatives via 1,3-dipolar cycloaddtion/SO₂ extrusion of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrile oxides is reported using 4 Å molecular sieves as dehydrochlorinating agent.

Protected zone ventilation and reduced personal exposure to airborne cross-infection

The main objective of this study was to examine the performance of protected zone ventilation (PZV) and hybrid protected zone ventilation (HPZV) to reduce the direct exposure to exhaled air from others' breathing. Experimental measurements are carried out to test the performance of PZV in a full-scale office room with two breathing thermal manikins. The measurements were performed under three configurations, including two standing manikins at different distances: 0.35, 0.5, and 1.1 m. When the supply air velocity is increased to 4 m/s in the downward plane jet, the dimensionless concentration is 40% lower than for fully mixed ventilation, which can be considered as a measure of protection from the zoning condition. The measurement results showed that in both the PZV and the HPZV system it is possible to decrease the transmission of tracer gas from one manikin to the opposite manikin; therefore, it probably would reduce the risk of air borne cross-infection between two people at the same relative positions. The results suggest that PZV and HPZV may be used to reduce the exposure of people in a protected zone from indoor pollutants emitted in a source zone.

Structural distortion-induced magnetoelastic locking in Sr(2)IrO(4) revealed through nonlinear optical harmonic generation

We report a global structural distortion in Sr_{2}IrO_{4} using spatially resolved optical second and third harmonic generation rotational anisotropy measurements. A symmetry lowering from an I4_{1}/acd to I4_{1}/a space group is observed both above and below the Néel temperature that arises from a staggered tetragonal distortion of the oxygen octahedra. By studying an effective superexchange Hamiltonian that accounts for this lowered symmetry, we find that perfect locking between the octahedral rotation and magnetic moment canting angles can persist even in the presence of large noncubic local distortions. Our results explain the origin of the forbidden Bragg peaks recently observed in neutron diffraction experiments and reconcile the observations of strong tetragonal distortion and perfect magnetoelastic locking in Sr_{2}IrO_{4}.

Experimental electronic structure of the metallic pyrochlore iridate Bi₂Ir₂O₇

Angle-resolved photoemission measurements have been performed on Bi2Ir2O7 single crystals, a metallic end-member of the family of pyrochlore iridates. The density of states, the Fermi surface, and the near-Fermi-level band dispersion in the plane perpendicular to the (1, 1, 1) direction were all measured and found to be in rough overall agreement with our LDA + SOC density functional calculations. Assuming that this same calculation approach will extend to other members of the pyrochlore iridates, the overall agreement we found increases the possibility that some of the novel predicted phases such as quantum spin-ice or Weyl Fermion states will exist in this family of compounds.

Coexistence of ferromagnetism and superconductivity in iron based pnictides: a time resolved magnetooptical study

Ferromagnetism and superconductivity are antagonistic phenomena. Their coexistence implies either a modulated ferromagnetic order parameter on a lengthscale shorter than the superconducting coherence length or a weak exchange coupling between the itinerant superconducting electrons and the localized ordered spins. In some iron based pnictide superconductors the coexistence of ferromagnetism and superconductivity has been clearly demonstrated. The nature of the coexistence, however, remains elusive since no clear understanding of the spin structure in the superconducting state has been reached and the reports on the coupling strength are controversial. We show, by a direct optical pump-probe experiment, that the coupling is weak, since the transfer of the excess energy from the itinerant electrons to ordered localized spins is much slower than the electron-phonon relaxation, implying the coexistence without the short-lengthscale ferromagnetic order parameter modulation. Remarkably, the polarization analysis of the coherently excited spin wave response points towards a simple ferromagnetic ordering of spins with two distinct types of ferromagnetic domains.

First Report of Myrothecium roridum Causing Leaf Spot of Anubias barteri var. nana in Mainland China

Anubias barteri var. nana (belonging to family Araceae) is one of the most popular ornamental plants for aquaria. It has slow growth and small attractive ornamental leaves. It originated from West Africa, was first described in 1860 by Heinrich Wilhelm Schott (1), and is now commercially planted widely in southern China. A new disease of A. barteri var. nana was observed on leaves. Approximately 30% of the plants in an ornamental nursery in Baiyun district, Gaungzhou, China (113°22'45.15″ E, 23°23'41.15″ N) in July 2013 were found to be infected. The pathogen caused necrotic spots that progressed to form holes on leaves of the infected plants, negatively affecting their ornamental market value. Eventually the diseased plant died. White fungal fruiting bodies and black sporodochia were observed on the surfaces of the symptomatic leaves. A single-spore isolate (myr5) was obtained from the concentric lesions and cultured on potato dextrose agar (PDA). The floccose fungal colonies were white to buff, and black conidiomata were often visible on the surface after 25 days of incubation. The conidia had rounded ends and the average size of conidia was 5.98 ± 0.15 × 2.24 ± 0.08 μm. The rDNA internal transcribed spacer (ITS) region of isolate myr5 was amplified by PCR using ITS1 and ITS4 primer pairs. The amplified product was sequenced and deposited in GenBank (Accession No. KJ572115) and showed 99% identity to Myrothecium roridum isolates BBA 71015 (AJ302001) and BBA 67679 (AJ301995) (unpublished), and 100% identity to the isolate myr2-2 from Dieffenbachia picta 'Camilla' in Taiwan (2). On the basis of morphological and molecular characterization, the fungus causing leaf spot on A. barteri var. nana plants was identified as M. roridum Tode ex Fr (2,3). To confirm the etiology of the disease, Koch's postulates was performed in a greenhouse (28 ± 2°C) using 3-day-old cultures of isolate myr5 and fungal spore suspensions of 1 × 10⁵ conidia ml^-1 containing 0.05% of Tween 20. Sixteen healthy leaves, two each from eight plants, were infiltrated on two different parts close to the midribs with 100 μl of the fungal spore using needleless syringes. Water infiltration was used as the control treatment. Water-soaked brown lesions appeared on leaves 7 days after inoculation, followed by the development of dark concentric rings within the necrotic areas on the surface of the inoculated leaves after 15 days of incubation. These symptoms were similar to those in the naturally infected aquarium plants. No symptoms were observed on any of the water micro-infiltrated plants. The fungus was re-isolated from the inoculated plants, but not from control plants. To our knowledge, this is the first report of Myrothecium leaf spot caused by M. roridum on A. barteri var. nana in mainland China. References: (1) W. Crusio. Primitiae Africanae XII 79 (14):1-48, 1979. (2) C. F. Hong et al. Plant Dis. 97:1253, 2013. (3) M. Tulloch. Mycol. Pap. 130:1-42, 1972.

Multimodal microscopy using 'half and half' contact mode and ultrasonic force microscopy

Advances in the design and fabrication of multifunctional nanostructured materials require characterization techniques capable of simultaneously mapping multiple material properties with nanoscale resolution. We show that this can be achieved by combining nanomechanical information from ultrasonic force microscopy (UFM) with simultaneously acquired friction force and conductivity measurements from contact mode scanning. This utilizes a 'half and half' approach, where the AFM is operated alternatively in UFM and contact mode, with the switching rate sufficiently fast that simultaneous contact mode and UFM information is acquired at each pixel of an image. We demonstrate the potential of such a multimodal approach through its application to composite systems consisting of graphene islands on a copper surface, single-walled carbon nanotubes (SWNTs) on a silicon oxide substrate, and a graphene epoxy composite. The half and half approach enables the friction force to be measured without topographical cross-talk. Application to the SWNT sample reveals a further advantage; due to the superlubricity of UFM it enables standard contact mode imaging techniques to be applied to delicate samples.

Fluorapatite-modified scaffold on dental pulp stem cell mineralization

In previous studies, fluorapatite (FA) crystal-coated surfaces have been shown to stimulate the differentiation and mineralization of human dental pulp stem cells (DPSCs) in two-dimensional cell culture. However, whether the FA surface can recapitulate these properties in three-dimensional culture is still unknown. This study examined the differences in behavior of human DPSCs cultured on electrospun polycaprolactone (PCL) NanoECM nanofibers with or without the FA crystals. Under near-physiologic conditions, the FA crystals were synthesized on the PCL nanofiber scaffolds. The FA crystals were evenly distributed on the scaffolds. DPSCs were cultured on the PCL+FA or the PCL scaffolds for up to 28 days. Scanning electron microscope images showed that DPSCs attached well to both scaffolds after the initial seeding. However, it appeared that more multicellular aggregates formed on the PCL+FA scaffolds. After 14 days, the cell proliferation on the PCL+FA was slower than that on the PCL-only scaffolds. Interestingly, even without any induction of mineralization, from day 7, the upregulation of several pro-osteogenic molecules (dmp1, dspp, runx2, ocn, spp1, col1a1) was detected in cells seeded on the PCL+FA scaffolds. A significant increase in alkaline phosphatase activity was also seen on FA-coated scaffolds compared with the PCL-only scaffolds at days 14 and 21. At the protein level, osteocalcin expression was induced only in the DPSCs on the PCL+FA surfaces at day 21 and then significantly enhanced at day 28. A similar pattern was observed in those specimens stained with Alizarin red and Von Kossa after 21 and 28 days. These data suggest that the incorporation of FA crystals within the three-dimensional PCL nanofiber scaffolds provided a favorable extracellular matrix microenvironment for the growth, differentiation, and mineralization of human DPSCs. This FA-modified PCL nanofiber scaffold shows promising potential for future bone, dental, and orthopedic regenerative applications.

Nitrosative Stress and Apoptosis by Intravenous Ferumoxytol, Iron Isomaltoside 1000, Iron Dextran, Iron Sucrose, and Ferric Carboxymaltose in a Nonclinical Model

Iron is involved in the formation as well as in the scavenging of reactive oxygen and nitrogen species. Thus, iron can induce as well as inhibit both oxidative and nitrosative stress. It also has a key role in reactive oxygen and nitrogen species-mediated apoptosis. We assessed the differences in tyrosine nitration and caspase 3 expression in the liver, heart, and kidneys of rats treated weekly with intravenous ferumoxytol, iron isomaltoside 1000, iron dextran, iron sucrose and ferric carboxymaltose (40 mg iron/kg body weight) for 5 weeks. Nitrotyrosine was quantified in tissue homogenates by Western blotting and the distribution of nitrotyrosine and caspase 3 was assessed in tissue sections by immunohistochemistry. Ferric carboxymaltose and iron sucrose administration did not result in detectable levels of nitrotyrosine or significant levels of caspase 3 vs. control in any of the tissue studied. Nitrotyrosine and caspase 3 levels were significantly (p<0.01) increased in all assessed organs of animals treated with iron dextran and iron isomaltoside 1000, as well as in the liver and kidneys of ferumoxytol-treated animals compared to isotonic saline solution (control). Nitrotyrosine and caspase 3 levels were shown to correlate positively with the amount of Prussian blue-detectable iron(III) deposits in iron dextran- and iron isomaltoside 1000-treated rats but not in ferumoxytol-treated rats, suggesting that iron dextran, iron isomaltoside 1000 and ferumoxytol induce nitrosative (and oxidative) stress as well as apoptosis via different mechanism(s).