Shortening Effect Research Articles

Better Droplet Deposition and Internode Shortening Effects of Plant Growth Regulator EDAH on Maize Applied by Small Unmanned Aerial Vehicle Than Electric Knapsack Sprayer

Maize (Zea mays L.) lodging is an important factor limiting its yield increase worldwide. EDAH (containing 27% ethephon and 3% DA-6) is commonly used to decrease lodging. There is an urgent need to select efficient application methods of agrochemical for better spray deposition. In our research, an unmanned aerial vehicle (UAV) (15 L ha−1 and 30 L ha−1) with EDAH dosages of 72 and 90 g a.i. ha−1, and electric knapsack sprayers (EKS) (450 L ha−1) with dosages of 90 g a.i. ha−1 were used to compare the droplet deposition distribution, uniformity and maize growth. According to our research, EDAH applied by UAV had a higher droplet deposition rate than EKS; EKS had a higher droplet coverage rate, deposition density, droplet distribution uniformity. At the same dosage of EDAH, the UAV had a better effect on controlling maize growth than EKS, and almost equal effects were detected when the dosage applied by the UAVs was decreased by 20%. Considering the lodging occurrence and yield, we recommend that the dosage of EDAH applied by UAVs should be 72 g a.i. ha−1 when there is weak lodging and 90 g a.i. ha−1 when there is heavy lodging, with a spray volume of 15 L ha−1.

The Effects of Differential Axial Shortening on RC High-rise Buildings with Outrigger or Mega Structure Systems

초고층 건물에서 수평변위 제어와 수직부재에서 발생하는 부등축소에 대한 검토가 필수적이다. 수평변위 제어를 위해 근래에 아웃리거 구조시스템과 메가 구조시스템을 횡력저항시스템으로 사용한 초고층 건물이 증가하고 있다. 또한, 부등축소로 인한 구조적 문제를 해결하기 위해 부등축소량 예측과 예측결과를 통한 시공단계에서의 보정방법이 연구되어 왔으나 부등축소에 대한 횡력저항시스템의 영향 비교는 드문 편이다. 따라서, 본 논문에서는 수평변위 제어를 위해 아웃리거 구조시스템과 메가 구조시스템을 사용한 60층 규모의 철근콘크리트 주거용 초고층 건물에 대해 시공단계해석을 통한 부등축소를 비교하고 그 영향을 분석하고자 한다. 또한, 부등축소는 비구조요소의 파손 및 구조요소에 부가하중을 유발하기도 하며 부등축소가 야기한 문제는 초고층 건물에서 중요한 부재를 손상시킬 수 있으므로 각 횡력저항시스템별로 수직부재의 부등축소에 대한 영향을 분석하였다.

Reaction-composite diffusion brazing of C-SiC composite and Ni-based superalloy using mixed (Cu-Ti)+C powder as an interlayer

Taking the advantages of reaction-composite brazing and transient liquid phase bonding (TLP), a novel process with the features of low-temperature bonding & high-temperature resisting was implemented to join C-SiC composite and GH4169 superalloy. In the new process, mixed powder of low-melting-point Cu85Ti15 alloy and carbon (C) was used as an interlayer. At a relatively low bonding temperature (990 °C), in-situ reaction of (Cu-Ti) l +C s →(Cu) s +TiC s and interdiffusion between the (Cu-Ti) l liquid and the GH4169 substrate concurrently occurred to transform the interlayer into a TiC-reinforced (Cu) s matrix composite joining layer. The low-CTE reinforcement TiC helped to alleviate the high residual stress in the joint, and the (Cu) s matrix provided the high-temperature resistance for the joint. In the current work, microstructural behavior, formation mechanism, heat resistance and shear strengths of the bonded joints were investigated. Results indicated that the (Cu-Ti) l /C s in-situ reaction had an effect of shortening the solidification time of the joining layer, thus decreasing the formation of Ti-C and Ti-Si brittle compounds at the C-SiC side interface. The bonded joints exhibited excellent comprehensive properties: melting temperature of the joining layer reached 1052 °C, which was much higher than that of Cu85Ti15 alloy (898 °C) and the bonding temperature (990 °C); the maximum shear strength at room temperature and 900 °C reached 234 MPa and 101 MPa, respectively.

Numerical simulation on the spontaneous ignition of high-pressure hydrogen release through a tube at different burst pressures

Spontaneous ignition induced by high-pressure hydrogen release is one of the huge potential risks in the promotion of hydrogen energy. However, the understanding of the microscopic dynamic characteristics of spontaneous ignition, such as ignition initiation and flame development, remains unresolved. In this paper, the spontaneous ignition caused by high-pressure hydrogen release through a tube is investigated by two-dimensional numerical simulation at burst pressure ranging from 2.67 to 15 MPa. Especially, the thermal and species characteristics in hydrogen shock-induced ignition under different strengths of shock wave are discussed carefully. The results show that the stronger shock wave caused by higher burst pressure leads to larger heating area and higher heating temperature inside the tube, increasing the possibility of spontaneous ignition. The shortening effect of initial ignition time and initial ignition distance will decrease with the increase of the burst pressure. Ignition will be initiated when the temperature is raised to about 1350–1400 K under the heating effect of shock waves. It is also found that the ignition occurs under the lean-fuel condition firstly on the upper and lower walls of the tube. The flame branch after spontaneous ignition is observed in the mixing layer. Two ignition kernels show different characteristics during the process of combustion and flow. The evolution of HRR and mass fraction of key species (OH, H, HO2) are also compared to identify the flame front. The mass fraction of H has the better trend with HRR. It is suggested that H radical is a more reasonable choice as the indicator of the flame front.

The effect of shortening and lengthening round periods exercises in the development of special endurance and some pulse indicators in elite boxers

The researcher noticed some weakness in the special endurance of boxers, at the end of rounds, especially at the end of the last round, the researcher suggested special exercises using the method of shortening or lengthening the training rounds time, to develop special endurance and some pulse indicators, the researcher chose 14 boxers that were divided equally into two groups, control and experimental, the researcher used the times: (30 sec.), (60 sec.) and (90 sec.), with rest times between (15 sec. and 60 sec) and (4 minutes), (5 minutes), (6 Minutes) with rest times between (30 sec. to 90 sec.), The repetitions for each round were downwards according to the time period of the round, the researcher concluded that training using shortening and lengthening exercises time has a positive effect in developing the endurance level and some pulse indicators for boxers from the research sample.

Effects of muscle shortening on single-fiber, motor unit, and compound muscle action potentials

Even under isometric conditions, muscle contractions are associated with some degree of fiber shortening. The effects of muscle shortening on extracellular electromyographic potentials have not been characterized in detail. Moreover, the anatomical, biophysical, and detection factors influencing the muscle-shortening effects have been neither identified nor understood completely. Herein, we investigated the effects of muscle shortening on the amplitude and duration characteristics of single-fiber, motor unit, and compound muscle action potentials. We found that, at the single-fiber level, two main factors influenced the muscle-shortening effects: (1) the electrode position and distance relative to the myotendinous zone and (2) the electrode distance to the maxima of the dipole field arising from the stationary dipole created at the fiber-tendon junction. Besides, at the motor unit and muscle level, two additional factors were involved: (3) the overlapping between the propagating component of some fibers with the non-propagating component of other fibers and (4) the spatial spreading of the fiber-tendon junctions. The muscle-shortening effects depend critically on the electrode longitudinal distance to the myotendinous zone. When the electrode was placed far from the myotendinous zone, muscle shortening resulted in an enlargement and narrowing of the final (negative) phase of the potential, and this enlargement became less pronounced as the electrode approached the fiber endings. For electrode locations close to the myotendinous zone, muscle shortening caused a depression of both the main (positive) and final (negative) phases of the potential. Beyond the myotendinous zone, muscle shortening led to a decrease of the final (positive) phase. The present results provide reference information that will help to identify changes in MUPs and M waves due to muscle shortening, and thus to differentiate these changes from those caused by muscle fatigue.Graphical abstract

The Bur1 cyclin-dependent kinase regulates telomere length in Saccharomyces cerevisiae.

Telomere length regulation is essential for cell viability in eukaryotes. While many pathways that affect telomere length are known, we do not yet have a complete understanding of the mechanism of length regulation. To identify new pathways that might regulate telomere length, we carried out a genetic screen in yeast and identified the cyclin‐dependent kinase complex Bur1/2 as a regulator of telomere length. Mutations in either BUR1 cyclin‐dependent kinase or the associated BUR2 cyclin resulted in short telomeres. This regulation did not function through the known role of BUR1 in regulating histone modification as bur1∆ set2∆ and bur2∆ set2∆ double mutants rescued cell growth but did not rescue the telomere shortening effects. We found that both bur1∆ and bur2∆ set2∆ were also defective in de novo telomere addition, and deletion of SET2 did also not rescue this elongation defect. The Bur1/2 cyclin‐dependent kinase regulates transcription of many genes. We found that TLC1 RNA levels were reduced in bur2∆ set2∆ mutants; however, overexpression of TLC1 restored the transcript levels but did not restore de novo telomere elongation or telomere length. These data suggest that the Bur1/2 kinase plays a role in telomere elongation separate from its role in transcription of telomerase components. Dissecting the role of the Bur1/2 kinase pathway at telomeres will help complete our understanding of the complex network of telomere length regulation.

Impulse Response Shortening in TDOA Algorithm for Underwater Acoustic Localization

This paper presents a new idea of impulse response shortening in time difference of arrival (TDOA) measurement algorithm for underwater acoustic localization. Due to strong multipath interference caused by acoustic wave reflection, the pseudo-peaks occur when calculating a correlation function. Their pseudo-peaks disturbs the detection of a correct time position and leads to large TDOA measurement errors. In our previous paper, we presented the impulse response based GCC-PHAT (IR-GCC-PHAT), which computes a time difference by taking a cross-correlation between two impulse responses. As the further improvement, we study the effects of impulse response shortening that removes the pseudo-peaks. The effectiveness of impulse response shortening is explained by observing acoustic wave paths on an acoustic propagation simulator and verified by the simulation results

Potential for codends with shortened lastridge ropes to replace mandated selection devices in demersal trawl fisheries

In many trawl fisheries, codend size selectivity is supplemented by adding selection devices to the gear. In the Barents Sea gadoid fishery, combining diamond mesh codends with sorting grids is compulsory. However, the use of grids increases the costs and complexity of the gear, causing discontent among fishermen and prompting researchers to seek alternative solutions. Lastridge ropes are ropes attached to the selvedges of the codend. In this study, we tested the effect of shortening the lastridge ropes of two diamond mesh codends with different mesh sizes on the size selectivity of cod (Gadus morhua), haddock (Melanogramus aeglefinnus), and redfish (Sebastes spp.). Shortening the lastridge ropes by 15% increased the mesh opening during the fishing process, which significantly improved the size-selective properties of the codends. Further, the L50 values were always higher for the codends in the short lastridge configuration. Therefore, codends with shortened lastridge ropes may be a simpler alternative to sorting grids in this fishery, and they may be applicable to many other fisheries in which additional selection devices are used.

D-mannose suppresses oxidative response and blocks phagocytosis in experimental neuroinflammation

Inflammation drives the pathology of many neurological diseases. d-mannose has been found to exert an antiinflammatory effect in peripheral diseases, but its effects on neuroinflammation and inflammatory cells in the central nervous system have not been studied. We aimed to determine the effects of d-mannose on key macrophage/microglial functions-oxidative stress and phagocytosis. In murine experimental autoimmune encephalomyelitis (EAE), we found d-mannose improved EAE symptoms compared to phosphate-buffered saline (PBS)-control mice, while other monosaccharides did not. Multiagent molecular MRI performed to assess oxidative stress (targeting myeloperoxidase [MPO] using MPO-bis-5-hydroxytryptamide diethylenetriaminepentaacetate gadolinium [Gd]) and phagocytosis (using cross-linked iron oxide [CLIO] nanoparticles) in vivo revealed that d-mannose-treated mice had smaller total MPO-Gd+ areas than those of PBS-control mice, consistent with decreased MPO-mediated oxidative stress. Interestingly, d-mannose-treated mice exhibited markedly smaller CLIO+ areas and much less T2 shortening effect in the CLIO+ lesions compared to PBS-control mice, revealing that d-mannose partially blocked phagocytosis. In vitro experiments with different monosaccharides further confirmed that only d-mannose treatment blocked macrophage phagocytosis in a dose-dependent manner. As phagocytosis of myelin debris has been known to increase inflammation, decreasing phagocytosis could result in decreased activation of proinflammatory macrophages. Indeed, compared to PBS-control EAE mice, d-mannose-treated EAE mice exhibited significantly fewer infiltrating macrophages/activated microglia, among which proinflammatory macrophages/microglia were greatly reduced while antiinflammatory macrophages/microglia increased. By uncovering that d-mannose diminishes the proinflammatory response and boosts the antiinflammatory response, our findings suggest that d-mannose, an over-the-counter supplement with a high safety profile, may be a low-cost treatment option for neuroinflammatory diseases such as multiple sclerosis.

Temporary prolongation of corrected QT interval after cardioneuroablation for functional bradyarrhythmias

Abstract Background There are controversial reports on QT interval response to ganglionic plexi ablation that are selectively targeted during cardioneuroablation (CNA) or occurs as collateral lesion during left atrial ablation procedures. Both shortening or prolongation of the heart-rate corrected QT interval (QTc) with therapeutic or safety implications were described. Purpose In this retrospective study, we investigated longitudinal changes of QTc after CNA. Methods The study included 108 patients (age: 39±12 years, 60% males) who underwent biatrial cardioneuroablation (radiofrequency time: 15.5±6.7 min) for symptomatic functional bradyarrhythmias. Surface ECG examinations were performed on the day before the CNA (N=108), 1 hour after the CNA (N=106), on the 1st post-ablation day (N=50), at the 3-month (N=99), and 1-year (N=63) follow-up visits. Automated measurements of QT interval were employed for the analysis. Four formulas (Bazett, Framingham, Fridericia, and Hodges) were used for the correction of QT interval to instant heart rate. Results QTc significantly prolonged immediately after the CNA with rapid return to baseline values (Figure and Table). This was particularly valid for QT correction by Framingham formula (and similarly for Fridericia and Hodges formulas). The QTc by Bazett formula, which is known to overestimate QT at higher heart rates, returned to baseline more slowly and incompletely. Several mechanisms may contribute to observed QTc dynamics: (1) direct effect of autonomic denervation with recovery phenomenon; (2) QT hysteresis with an extremely long time constant; or (3) artifact due to suboptimum QT correction to a substantial change of heart rate. Conclusions The study suggests that CNA produces acute prolongation of QTc interval with rapid decay and virtual normalization in 3 months. CNA in otherwise healthy subjects is not likely associated with substantial long-term risk of long-QT-associated arrhythmias. In the same way, we cannot confirm earlier observations of clinically significant QTc shortening effect of ganglionated plexi ablation. Funding Acknowledgement Type of funding sources: None. Figure 1Table 1

Examination about more realistic prognosis evaluation method, how long the patients with congestive heart failure can spend at home

Abstract Background From August 2015, for efficient medical care in congestive heart failure (CHF) cases, we had introduced a unique clinical pathway (PATH) provided the immediate use of Tolvaptan and comprehensive education by multi-disciplinary staff after admission. And by introduction of PATH, we confirmed the shortening effect of hospitalization period with CHF and the suppressive effect of readmission with CHF after discharge. But since almost CHF patients repeat hospitalization and discharge due to change of their medical condition, the investigation for only first readmission rate after discharge is not enough to assess the entire long clinical course of CHF. Recently we found one report about evaluation method for CHF clinical prognosis, how long CHF patients can stay healthy at their own home after discharge within a certain period. This evaluation method is considered to take into account the long clinical course of CHF. Purpose We investigated whether the CHF patients introduced PATH on admission could stay longer at their home than CHF patients without PATH. Methods Between April 2014 and July 2019, 471 CHF cases, who ware admitted in our hospital at first and could be followed up for at least 1 month after discharge, ware enrolled. We divided them to two groups, PATH- group before introducing PATH (until July 2015, 142 cases), and PATH+ group applied PATH (after August 2015, 329 cases). Between both groups, we investigated the readmission rate (RR) with CHF and the total period (TP) that patients could spend at home within1, 3, 6 and 12month after discharge. Results There were no significant differences in mean age, pre-hospital living status, or clinical status at admission between the two groups. On the other hand, due to efficient CHF care, the average length of hospital stay was significantly shorter (figure1). RR within 1, 3, 6 and 12 months after discharge ware all lower in PATH+ group. And TP within 1, 3, 6 and 12 months after discharge ware all longer in PATH+ group (figure2). Conclusion By introducing our unique clinical pathway for congestive heart failure cases requiring hospitalization, we could confirm not only the improvement of their conventional clinical prognosis index but also the improvement of their new and more realistic clinical prognosis index after discharge. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

A NOS1AP gene variant is associated with a paradoxical increase of the QT-interval shortening effect of digoxin.

Digoxin is characterized by a small therapeutic window and a QT-interval shortening effect. Moreover, it has been shown that the genetic variants of the nitric oxide synthase-1 adaptor protein (NOS1AP) gene are associated with QT-interval prolongation. We investigated whether the rs10494366 variant of the NOS1AP gene decreases the QT-interval shortening effect of digoxin in patients using this drug. We included 10,057 individuals from the prospective population-based cohort of the Rotterdam Study during a median of 12.2 (interquartile range (IQR) 6.7-18.1) years of follow-up. At study entry, the mean age was 64 years and almost 59% of participants were women. A total of 23,179 ECGs were longitudinally recorded, of which 334 ECGs were from 249 individuals on digoxin therapy. The linear mixed model analysis was used to estimate the effect of the rs10494366 variant on the association between digoxin use and QT-interval duration, adjusted for age, sex, RR interval, diabetes, heart failure, and history of myocardial infarction. In non-users of digoxin, the GG genotype was associated with a significant 6.5 ms [95% confidence interval (CI) 5.5; 7.5] longer QT-interval duration than the TT variant. In current digoxin users, however, the GG variant was associated with a significantly -23.9 [95%CI -29.5; -18.5] ms shorter mean QT-interval duration than in those with the TT variant with -15.9 [95%CI -18.7; -13.1]. This reduction was strongest in the high digoxin dose category [≥0.250 mg/day] with the GG genotype group, with -40.8 [95%CI -52.5; -29.2] ms changes compared to non-users. Our study suggests that the minor homozygous GGgenotype group of the NOS1AP gene rs10494366 variant is associated with a paradoxical increase of the QT-interval shortening effect of digoxin in a population of European ancestry.

Optimization of pasteurization of meat products using pasteurization values (p-values)

This study aimed to examine the effect of shortening the effective heat treatment time by 15 minutes for finely and coarsely chopped sausages and canned meat in pieces packed in polyamide casings with diameters of 75 and 90 mm. Product safety was ensured in accordance with legislation and with the producer food safety system. Optimization led to a decrease in p-values for finely chopped sausages (diameter 90: 148.8 → 97.64 minutes; diameter 75: 111.2 → 58.4 min), coarsely chopped cooked sausages (diameter 90: 115.5 → 79.1 min; diameter 75: 245.3 → 106.6 min) and for canned meat in pieces (diameter 90: 249.7 → 95.91; diameter 75: 213.9 → 48.42 min). The use of p-value in optimization confirms the pasteurization level and ensures the safety of the product in the defined storage conditions. It is also possible to compare the levels of heat treatment for different products that are differently packaged.

Investigating the effects of flexor tendon shortening on active range of motion after finger tendon repair.

Evaluation of surgical effects is often done using simple cadaver experimentation. This study uses a robotic testbed to estimate the best-case clinical outcomes of flexor tendon shortening during repair surgery on cadaver hands. Nine fresh-frozen cadaver subjects were connected to an extrinsic index finger robotic muscle testbed and measurement system. The flexor digitorum profundus tendons were severed and surgically repaired at different shortening levels. The index finger's extrinsic tendons were robotically actuated using Hill-type muscle models to emulate the muscle force-length relationships. Extensor muscles were then activated to estimate the active range of motion (ROM) of the all-finger joints after surgery. The effects of metacarpophalangeal (MCP) joint extension limits and extensor muscle activation were also investigated. The resulting interphalangeal joint ROM was clinically graded. Active ROM of the finger decreases as tendon shortening increases ( ), like passive ROM. This results in a clinical reduction of functionality grade from excellent to good at 10 mm of shortening. Blocking MCP joint ROM and extensor activation also showed significant effects on recovered ROM ( and 0.86). Significant two-way interactions were also observed between shortening and MCP joint blocking ( ) and between shortening and extensor activation ( ). Results support clinical recommendations of limiting shortening to 10 mm. While this article provides additional experimental evidence for current surgical recommendations, it also validates a new robotic-cadaver methodology for predicting active hand recovery in terms of clinical measurements.

Sodium channel blockers in the management of long QT syndrome types 3 and 2: A system review and meta-analysis.

β-Blockers are first-line therapy in patients with long QT syndrome (LQTS). However, β-blockers had genotype dependent efficacy (LQT1>LQT2>LQT3). Sodium channel blockers have been recommended as add-on therapy for LQT3 patients. However, the pooled effect of sodium channel blockers in all LQTS patients remains unknown. We conducted a systematic electronic search of PubMed, Embase, and the Cochrane Library. Fixed effects model was used to assess the effect of sodium channel blockers on QTc, cardiac events (CEs), and the proportion of QTc ≥ 500 ms and QTc ≤ 460 ms in LQTS patients. Pooled analysis of 14 studies with 213 LQTS (9 LQT1 + 63 LQT2 + 135 LQT3 + 6 others) patients showed that sodium channel blockers significantly shortened QTc by nearly 50 ms (mean difference [MD], -49.43; 95% confidence interval [CI], -57.80 to -41.05, p < .001), reduced the incidence of CEs (risk ratio [RR], 0.23; 95% CI, 0.11-0.47; p < .001) and the proportion of QTc ≥ 500 ms (RR, 0.33; 95% CI, 0.24-0.47; p < .001), and increased the proportion of QTc ≤ 460 ms (RR, 10.33; 95% CI, 4.62-23.09; p < .001). Sodium channel blockers significantly shortened QTc both in LQT3 and LQT2 patients, while the QTc shortening effect in LQT3 was superior to that in LQT2 (57.39 vs. 36.61 ms). Mexiletine, flecainide, and ranolazine all significantly shortened QTc, and the QTc shortening effect by mexiletine was the best (60.70 vs. 49.08 vs. 50.10 ms). Sodium channel blockers can be useful both in LQT3 and LQT2 patients. Mexiletine, flecainide and ranolazine significantly shortened QTc in LQTS patients, and the QTc shortening effect by mexiletine was the best.

A Study on Multiple Factors Affecting the Accuracy of Multiclass Skin Disease Classification

Diagnosis of skin diseases by human experts is a laborious task prone to subjective judgment. Aided by computer technology and machine learning, it is possible to improve the efficiency and robustness of skin disease classification. Deep transfer learning using off-the-shelf deep convolutional neural networks (CNNs) has huge potential in the automation of skin disease classification tasks. However, complicated architectures seem to be too heavy for the classification of only a few skin disease classes. In this paper, in order to study potential ways to improve the classification accuracy of skin diseases, multiple factors are investigated. First, two different off-the-shelf architectures, namely AlexNet and ResNet50, are evaluated. Then, approaches using either transfer learning or trained from scratch are compared. In order to reduce the complexity of the network, the effects of shortening the depths of deep CNNs are investigated. Furthermore, different data augmentation techniques based on basic image manipulation are compared. Finally, the choice of mini-batch size is studied. Experiments were carried out on the HAM10000 skin disease dataset. The results show that the ResNet50-based model is more accurate than the AlexNet-based model. The transferred knowledge from the ImageNet database helps to improve the accuracy of the model. The reduction in stages of the ResNet50-based model can reduce complexity while maintaining good accuracy. Additionally, the use of different types of data augmentation techniques and the choice of mini-batch size can also affect the classification accuracy of skin diseases.

Shortening effect influence of Distal Minimally Invasive Metatarsal Osteotomy in primary metatarsalgia

In primary metatarsalgia, Distal Minimally invasive Metatarsal Osteotomy (DMMO) achieves a correct load distribution which is a factor in pain relief, but contrary to the elevation of the metatarsal head, shortening the metatarsal length has no influence on plantar-loading parameters, while the increased metatarsal length is a factor in the development of metatarsalgia. Thus, we hypothesized that metatarsalgia could be partly related to a functional imbalance between bone structure and soft tissues and pain relief after DMMO results from soft tissue relaxation. Many authors have highlighted the correlation between joint pressure and periarticular soft tissue tension. To test our hypothesis, we measured intra-operatively the MTPJ pressure of 19 patients suffering from primary metatarsalgia, before and after DMMO. This pressure is being analyzed as a reflection of joint decompression and forefoot soft tissue release. Many authors have highlighted the correlation between joint pressure and periarticular soft tissue tension. Lower metatarsals presenting metatarsalgia show a significantly lower MTPJ pressure compared to asymptomatic rays, and DMMO induces a significant increase of MTPJ pressure. Those variations reflect the functional imbalance between bone structure and soft tissue in primary metatarsalgia. The biomechanical rationale of the shortening effect of DMMO could therefore be explained by the release of forefoot soft tissue, which could take part in the pain relief by restoring this balance.

Are we neglecting long-term effects of vertebral shortening on pulmonary function in spinal tuberculosis?

In developing part of the world, it is common to see complete destruction of vertebral bodies in tuberculosis. Our study aims to assess the effect of spinal tuberculosis with vertebral shortening on pulmonary function. Fifty cases of spinal TB (14 males, 36 females) managed both operatively and non-operatively, who presented to tertiary care institute between years 2011 and 2016 were assessed. Vertebral height loss was assessed by spinal deformity index (SDI). All patients underwent pulmonary function testing using same equipment sitting in upright position. Mean age was 27.9years (27.9 ± 11.9). 11 patients with mean SDI of 2.7 ± 1.1 showed normal lung function. 36 patients showed restrictive pattern of which 12 were mild, 14 were moderate and 10 showed severe pattern with a mean SDI of 3.8 ± 1.2, 5.6 ± 1.3 and 6.1 ± 1.4, respectively. 3 cases showed obstructive pattern. As the apex of curve shifted proximally, FVC% reduced. Increase in SDI value was associated with a fall in the vital capacity and FEV1. Increase in the kyphotic angle was associated with a deleterious effect on PFT results. Risk stratification of pulmonary dysfunction resulting from vertebral body height loss due to kyphosis will emphasize the need for early detection of spinal tuberculosis before deformity occurs.

Effect of Active Lengthening and Shortening on Small-Angle X-ray Reflections in Skinned Skeletal Muscle Fibres.

Our purpose was to use small-angle X-ray diffraction to investigate the structural changes within sarcomeres at steady-state isometric contraction following active lengthening and shortening, compared to purely isometric contractions performed at the same final lengths. We examined force, stiffness, and the 1,0 and 1,1 equatorial and M3 and M6 meridional reflections in skinned rabbit psoas bundles, at steady-state isometric contraction following active lengthening to a sarcomere length of 3.0 µm (15.4% initial bundle length at 7.7% bundle length/s), and active shortening to a sarcomere length of 2.6 µm (15.4% bundle length at 7.7% bundle length/s), and during purely isometric reference contractions at the corresponding sarcomere lengths. Compared to the reference contraction, the isometric contraction after active lengthening was associated with an increase in force (i.e., residual force enhancement) and M3 spacing, no change in stiffness and the intensity ratio I1,1/I1,0, and decreased lattice spacing and M3 intensity. Compared to the reference contraction, the isometric contraction after active shortening resulted in decreased force, stiffness, I1,1/I1,0, M3 and M6 spacings, and M3 intensity. This suggests that residual force enhancement is achieved without an increase in the proportion of attached cross-bridges, and that force depression is accompanied by a decrease in the proportion of attached cross-bridges. Furthermore, the steady-state isometric contraction following active lengthening and shortening is accompanied by an increase in cross-bridge dispersion and/or a change in the cross-bridge conformation compared to the reference contractions.