Formation of highly concentrated heterogeneous flows during plasma deposition of powder materials

Most industrial installations for plasma spraying of powder materials are equipped by nozzles with local (radial) powder input into the thermal plasma jet generated by the plasma torch. Such a local input of the sprayed material significantly perturbs the flow of the plasma jet, and causes dispersion of temperature and velocity of the particles of the sprayed powder materials. This work presents study of high-temperature heterogeneous flows generated by the electric arc plasma torch PNK - 50 with an annular (circular) input unit of powder materials with their gas-dynamic focusing developed at ITAM SB RAS. The performed experiments proved that the annular injection of a powder material guarantees the stable formation of a highly concentrated flow of thermal plasma with particles of sprayed powder materials. The comparative analysis clearly showed the advantages of annular powder input unit with its gas-dynamic focusing. In contrast to local point injection, axisymmetric annular injection practically does not disturb the jet of thermal plasma and, thus, significantly increases the efficiency of interphase exchange.

Ultrasound-guided five-point injection of botulinum toxin for patients with trapezius hypertrophy

Objectives Our study aimed to explore the clinical therapeutic effects of ultrasound-guided five-point injection of botulinum toxin type A for patients with trapezius hypertrophy. Methods Twenty female patients diagnosed with trapezius hypertrophy were enrolled in this study. The thicknesses of the trapezius muscle were measured by using the ultrasound scanner to locate the thickest point of trapezius, followed by labelling the other four points around the first point. Botulinum toxin type A was injected bilaterally (50 IU/side, 5 points/side) in the trapezius muscle of these patients. The surgery effects were evaluated by thicknesses of the trapezius muscle, intramuscular needle electromyographic and electroneurographic examinations, appearance changes and patients’ satisfactions. Results Statistically significant differences in thicknesses of the trapezius muscle were observed at 4 weeks (p < 0.001), 12 weeks (p < 0.001), 20 weeks (p < 0.001), 28 weeks (p = 0.011), 36 weeks (p = 0.022), and 44 weeks (p = 0.032) after surgery. The latencies of trapezius muscle became longer at 12 weeks after surgery (left: 2.40 ms, right: 2.53 ms vs. left: 1.75 ms, right: 2.00 ms). Electroneurographic results showed amplitude reduction of compound muscle action potentials (CMAPs) at 12 weeks after surgery (left: 1.91 uV, right: 3.10 uV vs. left: 15.00 uV, right: 15.40 uV). Obvious appearance changes were revealed at 12 weeks after surgery. All of 80% patients were very satisfied, 15% patients were relatively satisfied, and 5% patients were not satisfied with the surgery. Conclusion Ultrasound-guided five-point injection of botulinum toxin type A might be effective for patients with trapezius hypertrophy.

Design and Validation of a Multi-Point Injection Technology for MR-Guided Convection Enhanced Delivery in the Brain

Convection enhanced delivery (CED) allows direct intracranial administration of neuro-therapeutics. Success of CED relies on specific targeting and broad volume distributions (VD). However, to prevent off-target delivery and tissue damage, CED is typically conducted with small cannulas and at low flow rates, which critically limit the maximum achievable VD. Furthermore, in applications such as gene therapy requiring injections of large fluid volumes into broad subcortical regions, low flow rates translate into long infusion times and multiple surgical trajectories. The cannula design is a major limiting factor in achieving broad VD, while minimizing infusion time and backflow. Here we present and validate a novel multi-point cannula specifically designed to optimize distribution and delivery time in MR-guided intracranial CED of gene-based therapeutics. First, we evaluated the compatibility of our cannula with MRI and common viral vectors for gene therapy. Then, we conducted CED tests in agarose brain phantoms and benchmarked the results against single-needle delivery. 3T MRI in brain phantoms revealed minimal susceptibility-induced artifacts, comparable to the device dimensions. Benchtop CED of adeno-associated virus demonstrated no viral loss or inactivation. CED in agarose brain phantoms at 3, 6, and 9 μL/min showed &gt;3x increase in volume distribution and 60% time reduction compared to single-needle delivery. This study confirms the validity of a multi-point delivery approach for improving infusate distribution at clinically-compatible timescales and supports the feasibility of our novel cannula design for advancing safety and efficacy of MR-guided CED to the central nervous system.

Therapeutic effect of duloxetine combined with ozone trigger point injection on fibromyalgia---A retrospective observational study

ImportanceFibromyalgia (FM) is a common clinical chronic disease, mainly manifested as generalized chronic muscle pain and discomfort throughout the body, often accompanied by various emotional disorders such as depression, anxiety, cognitive impairment and sleep disorder, which seriously affects the quality of life of patients. However, there has not been adequately good treatment methods in clinically, so it is urgent to seek a better treatment method. In this study, duloxetine combined with ozone pain point injection was used to treat FM patients, and the clinical efficacy of the patients was observed.ObjectiveTo determine whether duloxetine combined with ozone pain point injection is safe and efficacious in the treatment of Fibromyalgia.MethodsAccording to the final treatment plan selection, the patients diagnosed with FM in the Pain Department of Shiyan Taihe Hospital, were selected from July 2017 to July 2020. After communication and written consent, 66 patients were injected with drugs and ozone pain point. Actually 60 cases finished the study procedure and follow-up. The age ranged from 22 to 57 years, and the course of the disease ranged from 2 to 8 years. In this study, a crossover design was adopted, and random number table method was used to enter the group. The patients were randomly divided into duloxetine group (group D), ozone injection group (group O) and duloxetine-ozone injection group (group D+O), with 20 patients in each group. Each group was given corresponding treatment. VAS, FIQ, PSQI and HAMD scales were used to evaluate and calculate the number of pain points, so as to observe and evaluate the clinical efficacy of patients.ResultsIn terms of pain, there was no significant difference among the groups before treatment. After 2 weeks and 4 weeks of treatment, the VAS scores in each group were significantly lower than before intervention (F=324.365 P < 0.05). The number of pain points in each group was significantly lower than before intervention, and the difference was statistically significant (F=514.046 P &lt; 0.05). It was observed that the analgesic effect of duloxetine combined with ozone pain point injection in the treatment of fibromyalgia was better than that of single therapy. There was no significant difference in quality of life among the groups before treatment. After 2 weeks and 4 weeks of treatment, the FIQ of each group was significantly lower than that before intervention, and the difference was statistically significant (F = 324.365, P<0.05). It was observed that duloxetine combined with ozone pain point injection for fibromyalgia significantly improved the quality of life of patients, especially in terms of improving sleep, compared with treatment alone. At the end of 4 weeks of treatment, HAMD scores for depressive symptoms were significantly lower in all 3 groups than before intervention (F=1079.961, P<0.05), and loxetine combined with ozone pain point injection for fibromyalgia had a more significant antidepressant effect (F=5.089, P <0.05).ConclusionThis study confirmed that duloxetine combined with ozone pain-point injection can effectively relieve pain in patients with FM, significantly improve the accompanying symptoms of sleep disorder and depression, and improve the quality of life of patients, which is worthy of clinical promotion.

The Immediate Effect of Trigger Point Injection With Local Anesthetic Affects the Subsequent Course of Pain in Myofascial Pain Syndrome in Patients With Incurable Cancer by Setting Expectations as a Mediator

A trigger point injection (TPI) with local anesthetic in myofascial pain syndrome (MPS) often has the immediate effect of a decrease in pain. It is unknown whether the immediate effect of a decrease in pain affects the subsequent course of pain. It is also unknown whether expectations of a decrease in pain mediate such effects. We aimed to clarify how the effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of pain, and whether it increased expectations of a decrease in pain. This was a prospective, single-center, observational clinical trial. Patients with incurable cancer who visited the palliative care department and received TPI with local anesthetic for MPS were prospectively examined. We evaluated whether the immediate effect of a TPI with local anesthetic affects the subsequent course of pain in MPS by setting expectations as a mediator, using path analysis. From 2018 to 2020, 205 patients with incurable cancer received TPI for MPS. Of these, 58.1% of patients reported an immediate effect of decreased pain. Compared with the non-immediate effect group, the immediate effect group had higher expectations of a decrease in pain, and the higher expectation was maintained at 7 days (p &lt; 0.001). The percentage of patients with pain reduction at 7 days after TPI was 88.2% in the immediate effect group and 39.5% in the non-immediate effect group (p &lt; 0.001). The immediate effect of decreased pain had the greatest influence on pain reduction at 7 days, both directly (β = 0.194) and indirectly through increased expectations (β = 0.293), as revealed by path analysis. The effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of MPS pain in patients with incurable cancer by setting expectations as a mediator. There were limitations to the discussion of these findings because this was an observational study.

Participatory action imaging in increasing clinician confidence of trigger point dry needling or trigger point injection of muscles requiring use of intercostal blocking: A case report

Some clinicians privately report a lack of confidence of being able to safely perform trigger point dry needling (TrPDN) or trigger point injection (TrPI) on muscles that require intercostal blocking, presumably resulting in procedural underutilization. Participatory action imaging (PAI), combined with procedural training and literature review of adverse event incidence, can be a useful tool in enhancing clinician confidence. A 6’ 2”, 185 lbs, 53-year-old male clinician subject with a latissimus dorsi trigger point (TrP) and privately reported high anxiety of performing TrPDN using the intercostal blocking technique, was examined to determine how clinician subject confidence could be improved through PAI and education regarding the degree of coverage of the intercostal space and rib during intercostal blocking. The clinician subject was placed in a left lateral decubitus position and rib imaged with a Siemens Acuson S2000 Ultrasound system with an 18L6 16 Hz high definition linear probe without intercostal blocking, and subsequently with intercostal blocking during maximal exhalation and inhalation, respectively. During intercostal blocking with maximal exhalation, the pleural space and an additional 13% of each side of the rib’s superior and inferior borders were completely blocked by the examiner’s fingers. During intercostal blocking with maximal inhalation, the pleural space and an additional 3% of each side of the rib’s superior and inferior borders were completely blocked by the fingers of the clinician. On visual inspection and interpretation of the images (e.g., PAI), the clinician subject reported a “significant” decrease in self-reported anxiety in performing the intercostal blocking technique (STAI Y-1 score improvement to “low to no anxiety range”). While more study is needed to investigate how variation in patient anatomy (weight, height, and morphology), clinician anatomy (hand size), needle direction, and specific rib being used for influences patient safety, this case report presents PAI as a previously undescribed means for future research and clinician education regarding risk assessment of TrPDN or TrPI of muscles requiring intercostal blocking.