Effects of organic side group structures on the properties of poly(organophosphazenes)

Abstract Background Achieving optimal analgesia with few side effects is the goal of pain management after cesarean delivery. Intrathecal (IT) morphine is the current standard but ultrasound-guided quadratus lumborum block (QLB) may offer superior pain control with fewer side effects. This study compared the pain-free period after cesarean delivery among parturients who received spinal block with IT morphine, with IT morphine and bilateral QLB, or only bilateral QLB. Methods Parturients having elective cesarean delivery under spinal block were randomized and allocated into IT morphine 0.2 mg with sham QLB (Group IT), IT morphine 0.2 mg and bilateral QLB with 0.25% bupivacaine 25 ml in each side (Group IT+QLB), or bilateral QLB with 0.25% bupivacaine 25 ml in each side (Group QLB). A PCA pump was connected after completion of the QLB or sham block. The first time to PCA morphine requirement was recorded and compared. Results Eighty parturients were included. Analysis of Group QLB was terminated early because at the second interim analysis, median pain-free period was significantly shorter in Group QLB [hours (95%CI): 2.50 (1.04–3.96) in Group IT vs. 7.75 (5.67–9.83) in IT+QLB vs. 1.75 (0.75–2.75) in QLB (p < 0.001)]. The median (min, max) amount of morphine required during 24 h was 5.5 (0–25) in Group IT vs. 5.0 (0–36) in IT+QLB vs. 17.5 (1–40) mg in Group QLB (p < 0.001). In the final analysis the median pain-free period was 2.50 (1.23–3.77) hours (95%CI) in Group IT (n = 27) vs. 8.02 (5.96–10.07) in IT+QLB (n = 28). (p = 0.027). Conclusion US-QLB used in conjunction with IT morphine yielded a statistically significant longer median pain-free period compared with standard IT morphine alone. However, QLB alone provided inferior pain control compared with standard IT morphine. When combined with IT morphine, QLB could provide additional analgesic benefit as a part of multimodal analgesic regimen, especially during the early postoperative period. Trial registration ClinicalTrials.gov no. NCT03199170 Date registered on June 22, 2017. Prospectively registered.

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Strength of side-to-side and step-cut repairs in tendon transfers: biomechanical testing of porcine flexor tendons

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193420939068 ◽

2020 ◽

Vol 45 (10) ◽

pp. 1061-1065

Author(s):

Eivind Strandenes ◽

Peter Ellison ◽

Anders O. Mølster ◽

Nils R. Gjerdet ◽

Irene O. Moldestad ◽

...

Keyword(s):

Tensile Properties ◽

Testing Machine ◽

Biomechanical Testing ◽

Maximum Load ◽

Side Group ◽

Tendon Transfers ◽

Flexor Tendons ◽

Active Mobilization ◽

The Difference

The aim of the study was to compare side-to-side with step-cut repairs to determine how much of the width it is possible to remove and still keep the repair strong enough to start active mobilization. Porcine flexor tendons were used to create side-to-side, one-third step-cut and half step-cut repairs. There were 15 repairs in each group. The tensile properties of the constructs were measured in a biomechanical testing machine. All repairs failed by the sutures splitting the tendon longitudinally. The maximum load and stiffness were highest in the side-to-side group. Our findings suggest that the half step-cut repair can withstand the forces exerted during active unrestricted movement of the digits in tendons of this size. The advantage of the step-cut repair is reduced bulkiness and less friction, which might compensate for the difference in strength.

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Estimating latent group structure in time-varying coefficient panel data models

Econometrics Journal ◽

10.1093/ectj/utz008 ◽

2019 ◽

Author(s):

Jia Chen

Keyword(s):

Panel Data ◽

Data Models ◽

Panel Data Models ◽

Time Varying ◽

Clustering Method ◽

Varying Coefficient ◽

Varying Coefficients ◽

Time Varying Coefficients ◽

Latent Group ◽

Group Structures

Summary This paper studies the estimation of latent group structures in heterogeneous time-varying coefficient panel data models. While allowing the coefficient functions to vary over cross-sections provides a good way to model cross-sectional heterogeneity, it reduces the degree of freedom and leads to poor estimation accuracy when the time-series length is short. On the other hand, in a lot of empirical studies, it is not uncommon to find that heterogeneous coefficients exhibit group structures where coefficients belonging to the same group are similar or identical. This paper aims to provide an easy and straightforward approach for estimating the underlying latent groups. This approach is based on the hierarchical agglomerative clustering (HAC) of kernel estimates of the heterogeneous time-varying coefficients when the number of groups is known. We establish the consistency of this clustering method and also propose a generalised information criterion for estimating the number of groups when it is unknown. Simulation studies are carried out to examine the finite-sample properties of the proposed clustering method as well as the post-clustering estimation of the group-specific time-varying coefficients. The simulation results show that our methods give comparable performance to the penalised-sieve-estimation-based classifier-LASSO approach by Su et al. (2018), but are computationally easier. An application to a panel study of economic growth is also provided.

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New azo-dye containing side group copolymethacrylates

Macromolecular Chemistry and Physics ◽

10.1002/(sici)1521-3935(19980901)199:9<1943::aid-macp1943>3.0.co;2-c ◽

1998 ◽

Vol 199 (9) ◽

pp. 1943-1949 ◽

Cited By ~ 3

Author(s):

Uta Rodekirch ◽

Joachim Rübner ◽

Dietmar Wolff ◽

Jürgen Springer

Keyword(s):

Azo Dye ◽

Side Group

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