Infinite Self-Propulsion of Circularly On/Discharged Droplets.

Self-propulsion of droplets in a controlled and long path at a high-speed is crucial for organic synthesis, pathological diagnosis and programable lab-on-a-chip. To date, extensive efforts have been made to achieve droplet self-propulsion by asymmetric gradient, yet, existing structural, chemical, or charge density gradients can only last for a while (<50 mm). Here, this work designs a symmetrical waved alternating potential (WAP) on a superhydrophobic surface to charge or discharge the droplets during the transport process. By deeply studying the motion mechanisms for neutral droplets and charged droplets, the circularly on/discharged droplets achieve the infinite self-propulsion (>1000 mm) with an ultrahigh velocity of meters per second. In addition, after permutation and combination of two motion styles of the droplets, it can be competent for more interesting work, such as liquid diode and liquid logic gate. Being assembled into a microfluidic chip, the strategy would be applied in chemical synthesis, cell culture, and diagnostic kits.

Development of an Automated and Scalable Virtual Assistant to Aid in PPE Adherence: A Study with Implications for Applications within Anesthesiology.

Virtual assistants (VAs) are conversational agents that are able to provide cognitive aid. We developed a VA device for donning and doffing personal protective equipment (PPE) procedures and compared it to live human coaching to explore the feasibility of using VAs in the anesthesiology setting. An automated, scalable, voice-enabled VA was built using the Amazon Alexa device and Alexa Skills application. The device utilized voice-recognition technology to allow a touch-free interactive user experience. Audio and video step-by-step instructions for proper donning and doffing of PPE were programmed and displayed on an Echo Show device. The effectiveness of VA in aiding adherence to PPE protocols was compared to traditional human coaching in a randomized, controlled, single-blinded crossover design. 70 anesthesiologists, anesthesia assistants, respiratory therapists, and operating room nurses performed both donning and doffing procedures, once under step-by-step VA instructional guidance and once with human coaching. Performance was assessed using objective performance evaluation donning and doffing checklists. More participants in the VA group correctly performed the step of "Wash hands for 20 seconds" during both donning and doffing tests. Fewer participants in the VA group correctly performed the steps of "Put cap on and ensure covers hair and ears" and "Tie gown on back and around neck". The mean doffing total score was higher in the VA group; however, the donning score was similar in both groups. Our study demonstrates that it is feasible to use commercially available technology to create a voice-enabled VA that provides effective step-by-step instructions to healthcare professionals.

Noncontact Charge Shielding Knife for Liquid Microfluidics.

Multibehavioral droplet manipulation in a precise and programmed manner is crucial for stoichiometry, biological virus detection, and intelligent lab-on-a-chip. Apart from fundamental navigation, merging, splitting, and dispensing of the droplets are required for being combined in a microfluidic chip as well. Yet, existing active manipulations including strategies from light to magnetism are arduous to use to split liquids on superwetting surfaces without mass loss and contamination, because of the high cohesion and Coanda effect. Here, we demonstrate a charge shielding mechanism (CSM) for platforms to integrate with a series of functions. In response to attachment of shielding layers from the bottom, the instantaneous and repeatable change of local potential on our platform achieves the desired loss-free manipulation of droplets, with a wide-ranging surface tension from 25.7 mN m-1 to 87.6 mN m-1, functioning as a noncontact air knife to cleave, guide, rotate, and collect reactive monomers on demand. With further refinement of the surface circuit, the droplets, just as the electron, can be programmed to be transported directionally at extremely high speeds of 100 mm s-1. This new generation of microfluidics is expected to be applied in the field of bioanalysis, chemical synthesis, and diagnostic kit.

Photothermal Solid Slippery Surfaces with Rapid Self-Healing, Improved Anti/De-Icing and Excellent Stability.

Icing phenomenon that occurs universally in nature and industry gets a great impact on human life. Over the past decades, extensive efforts have been made for a wide range of anti-icing/deicing surfaces, but the preparation of anti-icing/deicing interfaces that combine stability, rapid self-healing and excellent anti-icing/deicing performance remains a challenge. In this study, a photothermal solid slippery surface with excellent comprehensive performance is prepared by integrating cellulose acetate film, carbon nanotubes with paraffin wax (CCP). Apart from the excellent anti-icing and deicing properties at -17 ± 1.0 °C under 1 sun illumination, the surface can further achieve deicing at temperatures as low as -22 ± 1.0 °C under infrared light. The fabricated surface also exhibits great stability when placed in harsh conditions such as underwater or ultra-low temperature environments for over 30 days. Even when suffering from physical damage, the prepared surface can rapidly self-repair under 1 sun illumination or near-infrared (NIR) illumination within 16.0 ± 1.5 s. Due to the rapid and repeatable self-healing performance, the lubricating properties of the interface material do not deteriorate even after 50 repeated abrasing-repairing cycles. The photothermal solid slippery surface possesses wide-ranging applications and commercial value at high latitude and altitude regions.

No Benefits of Adding Dexmedetomidine, Ketamine, Dexamethasone, and Nerve Blocks to an Established Multimodal Analgesic Regimen after Total Knee Arthroplasty.

BACKGROUND: An optimal opioid-sparing multimodal analgesic regimen to treat severe pain can enhance recovery after total knee arthroplasty. The hypothesis was that adding five recently described intravenous and regional interventions to multimodal analgesic regimen can further reduce opioid consumption. METHODS: In a double-blinded fashion, 78 patients undergoing elective total knee arthroplasty were randomized to either (1) a control group (n = 39) that received spinal anesthesia with intrathecal morphine, periarticular local anesthesia infiltration, intravenous dexamethasone, and a single injection adductor canal block or (2) a study group (n = 39) that received the same set of analgesic treatments plus five additional interventions: local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intraoperative intravenous dexmedetomidine and ketamine, and postoperatively, one additional intravenous dexamethasone bolus and two additional adductor canal block injections. The primary outcome measure was 24-h cumulative opioid consumption after surgery and secondary outcomes were other analgesics, patient recovery, functional outcomes, and adverse events. RESULTS: Opioid consumption was not different between groups at 24 h (oral morphine equivalents, mean ± SD; study: 23.7 ± 18.0 mg vs. control: 29.3 ± 18.7 mg; mean difference [95% CI], -5.6 mg [-2.7 to 13.9]; P = 0.189) and all other time points after surgery. There were no major differences in pain scores, quality of recovery, or time to reach rehabilitation milestones. Hypotensive episodes occurred more frequently in the study group (25 of 39 [64.1%] vs. 13 of 39 [33.3%]; P = 0.010). CONCLUSIONS: In the presence of periarticular local anesthesia infiltration, intrathecal morphine, single-shot adductor canal block and dexamethasone, the addition of five analgesic interventions-local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intravenous dexmedetomidine, intravenous ketamine, an additional intravenous dexamethasone dose, and repeated adductor canal block injections-failed to further reduce opioid consumption or pain scores or to improve functional outcomes after total knee arthroplasty.

Effect of intravenous dexamethasone on the anaesthetic characteristics of peripheral nerve block: a double-blind, randomised controlled, dose-response volunteer study.

BACKGROUND: Intravenous dexamethasone is thought to prolong the duration of peripheral nerve block, but the dose-response relationship remains unclear. The aim of this volunteer study was to evaluate the dose-response effect of i.v. dexamethasone on the prolongation of median nerve block. METHODS: In a double-blind, randomised controlled study, 18 volunteer subjects received two median nerve blocks separated by a washout period. One block was conducted alongside an infusion of saline and the other alongside i.v. dexamethasone 2, 4, or 8 mg. The primary outcome was time to return of normal pinprick sensation. Secondary outcomes included thermal quantitative sensory testing (QST) for the time to return of cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), area under QST curves, grip strength, and the incidence of adverse effects. RESULTS: The primary outcome, time to recovery of pinprick sensation, was similar between volunteers receiving saline or i.v. dexamethasone, regardless of dose (P=0.99). The time to recovery of QST milestones was similar between groups, although area under QST curves indicated prolongation of CDT (0 vs 8 mg, P=0.002) and WDT (0 vs 2 mg, P=0.008; 0 vs 4 mg, P=0.001; 0 vs 8 mg, P<0.001). There was no difference in motor recovery or adverse effects. CONCLUSIONS: Intravenous dexamethasone failed to significantly prolong the duration of pinprick anaesthesia regardless of dose. However, area under QST curve analysis indicated a dose-independent prolongation of CDT and WDT, the clinical significance of which is unclear. CLINICAL TRIAL REGISTRATION: NCT02864602 (clinicaltrials.gov).

Intermittent bolus versus continuous infusion popliteal sciatic nerve block following major foot and ankle surgery: a prospective randomized comparison.

BACKGROUND AND OBJECTIVES: Foot and ankle surgery is associated with severe pain that can be reduced with continuous popliteal sciatic nerve block. We tested the hypothesis that programmed intermittent bolus (PIB) delivery of local anesthetic provides superior analgesia to a continuous infusion (CI) regimen. METHODS: 60 patients undergoing major foot and ankle surgery were randomized to receive PIB (10 mL of ropivacaine 0.2% every 2 hours) or CI (5 mL/hour) continuous popliteal sciatic nerve block with patient-controlled regional analgesia (5 mL every 30 min as needed) provided for all. Primary outcome was the average of static and dynamic numerical rating scale (NRS) pain scores through 48 hours. Secondary outcomes included rest and movement NRS pain scores at different timepoints, opioid consumption, local anesthetic consumption, intensity of sensory and motor block, patient satisfaction and the incidence of opioid-related side effects. RESULTS: There was no significant difference in the primary outcome of average NRS pain score through 48 hours, opioid consumption or the volume of local anesthetic administered. Patients in group PIB had significantly decreased strength of toe dorsiflexion at 6 hours (p=0.007) and 12 hours (p=0.001) and toe plantarflexion at 12 hours (p=0.004). Patient satisfaction and the incidence of side effects was similar between groups. CONCLUSIONS: Both CI and PIB regimens provided excellent analgesia, low opioid consumption and high patient satisfaction. While there was no difference in analgesic outcomes, PIB dosing resulted in a more profound motor block. TRIAL REGISTRATION NUMBER: NCT02707874.

The analgesic efficacy of the transversalis fascia plane block in iliac crest bone graft harvesting: a randomized controlled trial.

BACKGROUND: Iliac crest bone graft (ICBG) harvesting is associated with significant perioperative pain and opioid consumption. This randomized controlled trial sought to determine if the transversalis fascia plane (TFP) block provides effective analgesia for anterior ICBG harvesting. METHODS: Fifty patients undergoing wrist fusion surgery with anterior ICBG harvesting were randomized to receive a TFP block with either 20 ml of 0.5% ropivacaine or 5% dextrose. Patients additionally received a brachial plexus block for primary surgical-site anesthesia and either a general or spinal anesthetic depending on patient preference. Primary outcomes of interest were perioperative opioid consumption (measured as intravenous morphine equivalents [IME]), pain intensity at the ICBG harvest site for up to 48 h postoperatively, and the incidence of persistent postoperative pain at 6 and 12 months after surgery. RESULTS: The TFP group used less opioid in the post-anesthetic care unit (PACU) (median 0 vs. 2.5 mg IME, P = 0.01) and in the first 8 h following PACU discharge (median 2.5 vs. 13.0 mg IME, P = 0.02). The patients who received a TFP block also had lower pain scores in PACU (median 0 vs. 4.0 out of 10, P < 0.001). Although opioid consumption and pain scores were lower in the TFP group at later timepoints, this difference was not statistically significant. Persistent pain at the ICBG site was reported in only 4.3% and 6.5% of all patients at 6 and 12 months, respectively. CONCLUSIONS: The TFP block provides effective early analgesia for anterior ICBG harvesting. The incidence of persistent postoperative pain was low.

A Virtual Reality Simulation Model of Spinal Ultrasound: Role in Teaching Spinal Sonoanatomy.

BACKGROUND AND OBJECTIVES: Ultrasound assessment of the lumbar spine improves the success of spinal and epidural anesthesia, especially for patients with underlying difficult anatomy. To assist with the teaching and learning of ultrasound-guided neuraxial anesthesia, we have created an online interactive educational model (http://www.usra.ca/vspine.php and http://pie.med.utoronto.ca/vspine). The aim of the current study was to determine whether the virtual spine model improved the knowledge of neuraxial anatomy and sonoanatomy. METHODS: After obtaining ethics board approval and written participant consent, 14 anesthesia trainees with no prior experience with spine ultrasound imaging were included in this study. Construct validity was assessed using a pretest/posttest design to measure the knowledge acquired from self-study of the virtual spine simulation modules. Two tests (A and B) with 20 multiple-choice questions were used either for the pretest or posttest, at random in order to account for possible differences in difficulty between the 2 tests. These tests were administered immediately before and after a 1-hour training session using the spine ultrasound model. RESULTS: Fourteen anesthesia trainees completed the study. Seven used test A as the pretest (group A), and 7 used test B as the pretest (group B). Both groups showed a statistically significant improvement (P < 0.05) in test scores after a 1-hour session with the spine ultrasound model. The mean scores were 55% (SD, 11.2%) on the pretest and 77% (SD, 8.7%) on the posttest. CONCLUSIONS: The study demonstrated that after 1 hour of self-study by the trainees on the spine ultrasound model test scores improved by 40%.

A Novel Error Model of Optical Systems and an On-Orbit Calibration Method for Star Sensors.

In order to improve the on-orbit measurement accuracy of star sensors, the effects of image-plane rotary error, image-plane tilt error and distortions of optical systems resulting from the on-orbit thermal environment were studied in this paper. Since these issues will affect the precision of star image point positions, in this paper, a novel measurement error model based on the traditional error model is explored. Due to the orthonormal characteristics of image-plane rotary-tilt errors and the strong nonlinearity among these error parameters, it is difficult to calibrate all the parameters simultaneously. To solve this difficulty, for the new error model, a modified two-step calibration method based on the Extended Kalman Filter (EKF) and Least Square Methods (LSM) is presented. The former one is used to calibrate the main point drift, focal length error and distortions of optical systems while the latter estimates the image-plane rotary-tilt errors. With this calibration method, the precision of star image point position influenced by the above errors is greatly improved from 15.42% to 1.389%. Finally, the simulation results demonstrate that the presented measurement error model for star sensors has higher precision. Moreover, the proposed two-step method can effectively calibrate model error parameters, and the calibration precision of on-orbit star sensors is also improved obviously.

Intravenous dexamethasone and perineural dexamethasone similarly prolong the duration of analgesia after supraclavicular brachial plexus block: a randomized, triple-arm, double-blind, placebo-controlled trial.

BACKGROUND AND OBJECTIVES: Perineural dexamethasone prolongs the duration of single-injection peripheral nerve block when added to the local anesthetic solution. Postulated systemic mechanisms of action along with theoretical safety concerns have prompted the investigation of intravenous dexamethasone as an alternative, with decidedly mixed results. We aimed to confirm that addition of intravenous dexamethasone will prolong the duration of analgesia after single-injection supraclavicular block compared with conventional long-acting local anesthetic alone or in combination with perineural dexamethasone for ambulatory upper extremity surgery. METHODS: Seventy-five patients were randomized to receive supraclavicular block using 30-mL bupivacaine 0.5% alone (Control), with concomitant intravenous dexamethasone 8 mg (DexIV), or with perineural dexamethasone 8 mg (DexP). Duration of analgesia was designated as the primary outcome. To test our hypothesis, the superiority of DexIV was first compared with Control and then with DexP. Motor block duration, pain scores, opioid consumption, opioid-related side effects, patient satisfaction, and block-related complications were also analyzed. RESULTS: Twenty-five patients per group were analyzed. The duration of analgesia (mean [95% confidence interval]) was prolonged in the DexIV group(25 hours [17.6­32.4]) compared with Control (13.2 hours [11.5­15.0]; P < 0.001) but similar to the DexP group (25 hours[19.5­30.5]; P = 1). [corrected] Both DexIV and DexP had reduced pain scores, reduced postoperative opioid consumption, and improved satisfaction compared with Control. CONCLUSIONS: In a single-injection supraclavicular block with long-acting local anesthetic, the effectiveness of intravenous dexamethasone in prolonging the duration of analgesia seems similar to perineural dexamethasone.

Ultrasound-guided transversus abdominis plane (TAP) block for laparoscopic gastric-bypass surgery: a prospective randomized controlled double-blinded trial.

BACKGROUND: Despite the laparoscopic approach, patients can suffer moderate to severe pain following bariatric surgery. This randomized controlled double-blinded trial investigated the analgesic efficacy of ultrasound-guided transversus abdominis plane (TAP) blocks for laparoscopic gastric-bypass surgery. METHODS: Seventy patients undergoing laparoscopic gastric-bypass surgery were randomized to receive either bilateral ultrasound-guided subcostal TAP block injections after induction of general anesthesia or none. All patients received trocar insertion site local anesthetic infiltration and systemic analgesia. The primary outcome was cumulative opioid consumption (IV morphine equivalent) during the first 24 h postoperatively. Interval opioid consumption, pain severity scores, rates of nausea or vomiting, and rates of pruritus were measured during phase I recovery, and at 24 and 48 h postoperatively. RESULTS: There was no difference in cumulative opioid consumption during the first 24 h postoperatively between the TAP (32.2 mg [95% CI, 27.6-36.7]) and control (35.6 mg [95% CI, 28.6-42.5]; P = 0.41) groups. Postoperative opioid consumptions during phase I recovery and the 24-48-h interval were similar between groups, as were pain scores at rest and with movement during all measured intervals. The rates of nausea or vomiting and pruritus were equivalent. CONCLUSIONS: Bilateral TAP blocks do not provide additional analgesic benefit when added to trocar insertion site local anesthetic infiltration and systemic analgesia for laparoscopic gastric-bypass surgery.

Recurrent hyalinizing clear cell carcinoma of the base of tongue with high-grade transformation and EWSR1 gene rearrangement by FISH.

Hyalinizing clear cell carcinoma (HCCC) is a rare, low-grade salivary gland tumor with clear cells and hyalinized stroma. Prognosis of HCCC is excellent with few cases metastasizing to the lymph nodes and lung. We present a case of a 61-year-old male with recurrent HCCC on the base of tongue. Histologic examination revealed sheets of clear and eosinophilic cells with a background of a myxoid-like matrix. In addition, large, bizarre malignant cells, focal necrosis, and atypical mitotic figures were identified. By immunohistochemistry, the clear cells were positive for CK18, EMA and vimentin, focally positive for CK7 and CD10, but negative for p63, HMWK, SMA and calponin. A metastatic renal cell carcinoma was considered a possibility but the tumor was called "poorly-differentiated carcinoma, NOS". The patient underwent primary radiotherapy. A recurrence was identified at 10 months follow-up. A biopsy of the recurrent tumor showed clear cell differentiation and a predominant cribriform pattern with focal cords of eosinophilic cells invading the stroma. In contrast to the original tumor, no mitotic figures, atypia or necrosis were identified. The combination of lower grade and different architectural patterns appeared markedly different than the previous biopsy and the immunohistochemical pattern was also different. The recurrent tumor showed diffuse positivity for p63 and HMWK. It was negative for CD10, vimentin, SMA and calponin. Fluorescence in situ hybridization (FISH) analysis was positive for rearrangement of the EWSR1 gene in both samples, confirming that this represented a recurrence of the same tumor. It also confirmed that the initial tumor was a HCCC with high-grade transformation.

Galectin-3-mediated xenoactivation of human monocytes.

BACKGROUND: Delayed xenograft rejection (DXR) remains a roadblock to successful xenotransplantation. A feature of DXR is early recruitment of monocytes to the xenograft. Naïve human monocytes can recognize and adhere to unstimulated porcine aortic endothelial cells (PAEC) more than human aortic endothelial cells, partly due to endothelial expression of the xenoantigen galactose-alpha(1,3)galactose-beta(1,4)GlcNAc-R (alpha-gal). Previous work from our laboratory has implicated galectin-3 as a candidate molecule on monocytes involved in initial recognition and adhesion of human monocytes to PAEC. METHODS: Flow cytometry was used to analyze monocyte activation and galectin-3 accumulation in PAEC. Reactive oxygen intermediate production was analyzed using dihydrorhodamine measured in a fluorescence plate reader. Western blotting was performed to determine galectin-3 secretion and expression by human monocytes. Immunofluorescence staining for the tight junction protein zona occludens-1 was used as a measure of PAEC monolayer integrity. RESULTS: We demonstrate that galectin-3 can be secreted from monocyte intracellular stores on contact with alpha-gal. Soluble galectin-3 binds PAEC partly by expression of alpha-gal. Binding is reduced on endothelium derived from alpha-gal knockout animals, but not completely. Competing terminal sugars expressed on human aortic endothelial cells such as sialic acid, may block galectin-3 binding. Furthermore, soluble galectin-3 activates monocytes in an autocrine/paracrine manner. Blocking galectin-3 reduces the activation of human monocytes. Finally, the inhibition of galectin-3 reduces monocyte-mediated endothelial injury on co-culture with PAEC. CONCLUSION: Galectin-3 plays a role in human monocyte activation and adhesion in the presence of PAEC, which may contribute to DXR. Additional transgenic strategies targeting galectin-3 ligands on porcine endothelium may be required to achieve optimal xenograft survival.

Human monocytes recognize porcine endothelium via the interaction of galectin 3 and alpha-GAL.

Monocytes are one of the key inflammatory cells recruited to xenografts and play an important role in delayed xenograft rejection. Previous studies have demonstrated the ability of monocytes to bind to the major xenoantigen Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R; however, the receptor that mediates this interaction has yet to be identified. We provide evidence that it is Galectin-3, a approximately 30-kDa lectin that recognizes beta-galactosides (Gal-beta(1-3/4)GlcNAc) and plays diverse roles in many physiological and pathological events. Human monocyte binding is strikingly increased on porcine aortic endothelial cells (PAEC), which express high levels of Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R, compared with human aortic endothelial cells. Human monocytes obtained from healthy donors bind to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R at variable intensities. This variation of binding intensity was consistent and reproducible in individual donors. Galectin-3 is mainly expressed in human monocytes, not lymphocytes. Purified Galectin-3 is able to bind directly to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R. Galectin-3 can also be affinity isolated from monocytes (and not lymphocytes) using an Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R-biotin/streptavidin-bead pull-down system. Soluble Galectin-3 binds preferentially to PAEC vs human aortic endothelial cells, and this binding can be inhibited by lactose, indicating dependence on the carbohydrate recognition domain of Galectin-3. Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R is at least partly responsible for this phenomenon, as binding decreased after digestion of PAEC with alpha-galactosidase. Furthermore, monocytes pretreated with a blocking anti-Galectin-3 Ab show decreased adhesion to PAEC when compared with isotype control in a parallel plate flow chamber perfusion assay. Thus, we conclude that Galectin-3 expressed in human monocytes is a receptor for the major xenoantigen (Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R), expressed on porcine endothelial cells.

Monocyte adhesion to xenogeneic endothelium during laminar flow is dependent on alpha-Gal-mediated monocyte activation.

Monocytes are the predominant inflammatory cell recruited to xenografts and participate in delayed xenograft rejection. In contrast to allogeneic leukocytes that require up-regulation of endothelial adhesion molecules to adhere and emigrate into effector tissues, we demonstrate that human monocytes adhere rapidly to unstimulated xenogeneic endothelial cells. The major xenoantigen galactosealpha(1,3)galactosebeta(1,4)GlcNAc-R (alpha-gal) is abundantly expressed on xenogeneic endothelium. We have identified a putative receptor for alpha-gal on human monocytes that is a member of the C-type family of lectin receptors. Monocyte arrest under physiological flow conditions is regulated by alpha-gal, because cleavage or blockade results in a dramatic reduction in monocyte adhesion. Recruitment of human monocytes to unactivated xenogeneic endothelial cells requires both alpha(4) and beta(2) integrins on the monocyte; binding of alpha-gal to monocytes results in rapid activation of beta(2), but not alpha(4), integrins. Thus, activation of monocyte beta(2) integrins by alpha-gal expressed on xenogeneic endothelium provides a mechanism that may explain the dramatic accumulation of monocytes in vivo.