反射スペクトルからのＫ‐Ｋ変換による光学定数の算出誤差

To evaluate the biomechanical effects of platform switching on external- and internal-connection implants with regard to strain around the implants under loading. Implant analogs (5.0 × 12 mm) with external (EX) and internal (IN) connections were embedded into an acrylic resin block that simulated an edentulous ridge. Abutments with diameters of 5.0, 4.2, and 3.7 mm were attached to EX and IN analogs. A 100-N lateral load was applied to each abutment at an angle of 30 degrees, and the experiments were repeated 10 times. Strain gauges were attached to the implant surface at 1 mm (neck area) and 8 mm (apex area) below the platform to measure the strain around the implant under loading. Statistical analyses were performed by one-way analysis of variance and Steel-Dwass test. P < .05 was considered statistically significant. Significantly higher strain values were found around the neck area in both analogs (EX, -682.8 Με; IN,-582.1 Με) with conventional matching 5-mm-diameter abutments, followed by the analogs with 4.2-mm-diameter (EX, -184.1 Με; IN, -229.1 Με) and 3.7-mm-diameter (EX, -150.5 Με; IN, -129.7 Με) platform-switched abutments; this was statistically significant for EX (P < .05). In the apex area, a mild increase in strain was found with a decrease in abutment diameter, but no significant difference was found between 4.2- and 3.7-mm-diameter abutments for IN (P > .05). Within the limitations of this study, platform switching reduced strain surrounding the implant neck area in both EX and IN during loading. However, the decreases in strain values were greater with EX than with IN.

The infrared spectra of thin solid films of carotenoids on supports were investigated using multiple attenuated total reflection (ATR) spectroscopy technique. The specimens were obtained by the evaporation of 1 or 2 drops of appropriate solution of carotenoid on the both sides of quickly rotating ATR element. The carotenoids investigated were β-carotene, canthaxanthin, and lycopene. Retinal and retinyl acetate as related compounds were also studied. Multiple ATR infrared spectra of amorphous and crystalline films were recorded and compared with the corresponding spectra of the compounds in solutions and in bulk crystalline state (in KBr disks). The spectra of amorphous films were shown to be almost identical to the spectra of investigated compounds in solutions whereas in the spectra of crystalline (or partly crystalline) films the same band splittings as in the spectra of crystalline specimens appear. The values of the effective film thickness were calculated for all the compounds investigated and it was shown that the films studied were thin surface ones. The ATR technique was applied to the investigation of reactivity of the polyenes, patrticularly with the atmospheric oxygen in the dark and under illumination by visible and ultraviolet light. The oxidation is accompained by the graduate disappearence of the δ=C-H absorption band at 966 cm−1. The consumption of polyenic double bonds is accompained by the formation of carbonyl and hydroxyl absorption bands. Mechanisms of the initial stages of the process are proposed for different polyenes.

ObjectiveThe Thessaly test is a commonly used orthopedic test for meniscus tear evaluation. The study’s objective is to evaluate the degree of medial meniscal extrusion during different loading phases of the Thessaly test.MethodsA convenience sample of 60 healthy knees (35 participants) was examined and the data sets were collected from October 8, 2018 through February 8, 2019. Sonographic measurement of the degree of physiologic extrusion of the medial meniscus deep to the medial collateral ligament was taken by two examiners at six different loading phases: supine, standing, 5° knee-flexion with internal (IR)/external (ER) rotation and 20° knee-flexion with IR/ER. The difference in meniscal extrusion by knee position was compared with ANOVA. Interexaminer reproducibility assessment was analyzed using limits of agreement.ResultsThe mean meniscal extrusion for each position was—supine: 2.3 ± 0.5 mm, standing: 2.8 ± 0.8 mm, 5° IR: 2.3 ± 0.9 mm, 5° ER: 2.4 ± 0.7 mm, 20° IR: 1.9 ± 0.8 mm, and 20° ER: 2.3 ± 0.7 mm. Significant increase in extrusion was observed from supine to standing (p < 0.05) and from 20° IR to 20° ER (p = 0.015). Significant decreased measurement was observed from standing to 5° IR (p < 0.05), 5° ER (p < 0.05), 20° IR (p < 0.05) and 20° ER (p < 0.05). There is no significant change between 5° IR and 5° ER (p = 1.0). Agreement parameters revealed that the differences between examiner measurements were minimal; 75% of both examiners’ meniscal extrusion measurements were within 1.0 mm with 97% of measurements falling within 2.0 mm.ConclusionOur study’s novel findings showed various degrees of physiological extrusion of the medial meniscus in asymptomatic knees during the loading phases involved in the Thessaly test. Physiological MME does exist and should not be defaulted to pathologic meniscus as previously described. Agreement parameters suggest that measurement of meniscal extrusion during the Thessaly test is reproducible between different examiners.

AM bundle controls the anterior–posterior and rotational stability to a greater extent than the PL bundle — A cadaver study

Knee proprioception is an integral component of neuromuscular control system that stabilizes the joints, reducing incidence of injury. Knee injuries' incidences differ between genders. Knee rotation is a component of different knee injury mechanisms. Gender differences in knee proprioception in internal (IR) and external (ER) rotations are not sufficiently studied. To check whether proprioceptive acuity in IR and ER directions of knee rotation is inherently lower in women compared to men. Moreover, to assess gender difference in ranges of knee rotation. Thirty volunteers (15 women and 15 men) participated. Knee proprioception acuity and ranges of knee rotation were assessed using the knee rotatory kinesthetic device (KRKD). Proprioception was tested using absolute judgment task, subject's ability to discriminate different rotation movements (stimuli) randomly presented, then just notable difference (JND) was calculated; least difference accurately discriminated in 75% of trials. Women had lower proprioception acuity in IR than men (1.70∘± 0.79∘ and 1.12∘± 0.32∘, p= 0.011) respectively. Active IR (women: 41.29∘± 7.46∘, men 32.80∘± 3.64∘, p= 0.000), and passive IR (women: 53.43∘±11.67∘, men: 37.94∘± 5.22∘, p= 0.000) were higher in women compared to men. Active ER (women: 49.71∘± 11.37∘, men: 39.16∘± 5.46∘, p= 0.003), and passive ER (women: 62.29∘± 13.74∘, men: 48.89∘± 7.09∘, p= 0.002) were, also, higher in women. Gender difference in knee proprioception acuity was found in IR, which is the direction of rotation that anterior cruciate ligament (ACL) stabilize. Women's ranges of knee rotation are greater than men in both IR and ER.

The advancement of thin-film electro-optic (EO) materials and devices depends on reliable characterization and a thorough understanding of structure–property relationships that govern their EO performance. Here, we reinvent the attenuated total reflection (ATR) technique using the prism coupler method, which was proposed over three decades ago but remained largely underdeveloped, for standard characterization of thin-film EO coefficients (r₃₃ and r₁₃). The ATR technique detects the optical modes of a sharp drop in reflectivity (R) at specific critical angles in the spectrum, caused by the evanescent wave at the prism/air interface coupling into the slab waveguide through optical tunneling. For EO waveguides, substantial reflectivity change (&Delta;R) of ATR modes can be induced by small refractive index changes (&Delta;n of 10^-4 to 10^-3 ) of the Pockels effect at the extrema of first or second derivatives, enabling efficient lock-in-free detection and determination of r-coefficients. Further multi-mode and frequency-selective ATR measurements on benchmark EO materials, including thin-film lithium niobate (TFLN) and EO polymer SEO100, led to the accurate determination of r-coefficients. The study validates the Gaussian function as a better model for representing the ATR spectra of waveguide films, providing a global approximation of optical modes than the traditional Taylor expansions. Compared to the Teng-Man reflection technique, the new ATR technique stands out for its improved accuracy, high traceability, effective self-calibration, simple instrumentation, rapid data processing, quantitative determination of both surface plasmon resonance mode and dielectric slab waveguide modes, and for organic electro-optic materials, obtaining primary molecular properties of push-pull chromophores for materials development.

An optical fiber sensor based on attenuated total reflectance (ATR) for extraction chemical information from highly scattering turbid materials has been evaluated. The influence of particles on bulk absorption and ATR transmitted spectra of micron-sized graphite flakes and spherical glassy carbon suspensions were investigated. The ATR transmitted spectra of coiled fiber-optic sensor in those suspensions with various concentrations are insensitive to scattering of suspended particles, especially for graphite flake suspensions. The reason for different influence of graphite flakes and spherical glassy carbon particles suspensions on e ATR spectra analyzed. This study demonstrates that fiber-optic sensor based on ATR technique is a feasible technique in application for monitoring turbid suspensions.

Objectives:The objective of the study was to create a cadaveric model of hip capsule laxity and evaluate the biomechanical effects of a capsular shift used to treat hip instability on this model.Methods:Eight fresh frozen cadaveric hips, average age 58.5, were tested with a custom hip jig. To create the hip laxity model, the capsule was stretched in extension under 35Nm of torque for 1 hour in neutral rotation. Specimens went through a series of six testing conditions: intact, vented, stretched, capsulotomy, side to side repair, and capsular shift. Specimens were tested in internal (IR) and external (ER) rotational range of motion under 1.5 Nm of torque at 5 positions: 5° extension, 0°, 15°, 30° and 45° flexion. Maximum extension was measured at 5Nm torque, and femoral distraction under 40N and 80N of force. Following creation of the instability model, capsulotomy was performed just distal to and in line with the labrum from 12 o’clock to 4 o’clock through the entire substance of the iliofemoral ligament. Capsulotomies underwent two repairs, including a 1 cm capsular shift technique and side to side repair using #2 vicryl. Statistical analysis was performed using repeated measures ANOVA with TUKEY post-hoc analysis.Results:Analysis of the “stretched” state showed significantly increased IR at 5° ext, 0° flex, 15° flex, and 30° flex and increased distraction at 40N and 80N as compared to intact (Figure 1)(Table 1). Max extension increased by 6.6° between intact and stretched, however this was not statistically significant. Capsulotomy condition significantly increased ER and IR from intact at all flexion-extension positions. Furthermore, capsulotomy increased distraction at 40N and 80N, as well as max extension, as compared to intact. The repair restored IR back to the stretched state but not to the intact state at 5° ext and 0° flex (19.6° vs 24.5° and 21.8° vs 26.4°, respectively). The capsular shift significantly decreased IR compared to stretched state at 5° ext, 0°, and 15° flex, and at 5° ext and 0° compared to the vented state. Capsular shift restricted IR significantly more than repair at 5° ext, 0° flex, and 15° flex. Capsule shift and repair had similar effects on ER. Distraction distance at 40N and 80N was greater in the repair compared to the shift but this was not statistically significant. The capsular shift decreased distraction as compared to the stretched state but the repair did not. Maximum extension was significantly reduced back to the intact/vented state from the laxity state in the capsular shift but not in the repair.Conclusion:The instability model (stretched) was shown to have significantly greater range of motion, extension, and distraction than the intact condition. The greatest effects of capsular shift are seen with internal rotation, extension, and distraction with minimal effect on external rotation. The biomechanical effects of the capsular shift procedure in hip laxity patients show that its use can safely treat pathologic hip capsular laxity.

Transient and long-time kinetic responses of the cadaveric leg during internal and external foot rotation

Background: Water-polo is the water sport with the highest incidence of injuries, with shoulder pain being the most common one. The understanding of risk factors and guidance on preventive measures is essential in this sport discipline. The aim of this study was to determine the effects of a specific 6-week training plan on range of motion (ROM) and joint strength levels in a group of professional water-polo players. Methods: Quasi-experimental study with a sample of 28 participants (age: 20.1 ± 2.5 years; height: 176.9 ± 6.2 cm; body mass: 74.6 ± 8.1 kg). Three study groups, which consisted of one control group and two experimental groups, were established. Two repeated measurements, pre and post intervention, were performed. During these measurements, ROM of the glenohumeral joint was analyzed both in external (ER) and internal (IR) rotation, as well as the maximal isometric strength. Conclusions: The application of a training program improved glenohumeral joint ROM. ER and IR evolve differently in both shoulders. ER improved only in the throwing arm only in the group undergoing intervention but for the non-dominant side, improvements were observed in both ER and IR, regardless of whether or not they had followed the intervention plan. No improvements were observed in either the isometric strength or contralateral asymmetries.

BackgroundThere are limited studies reporting descriptive strength and range of motion in youth baseball players 12 years of age or younger.PurposeTo establish normative data for external (ER) and internal (IR) rotation range of motion (ROM), total arc range of motion (TROM), and isometric rotator cuff strength in youth baseball players, and to compare between the dominant throwing arm (D) to the non-dominant arm (ND).Study DesignCross-sectionalMethodsPatient population included 50 (5 to 12-year-old) uninjured, healthy athletes. ROM measurements were performed preseason using a goniometer for IR and ER in the supine position with the shoulder in 90 degrees of abduction (abd) with scapular stabilization. Isometric strength measurements for IR and ER were collected in both neutral and 90 degrees (deg) of abduction with the use of a hand-held dynamometer and recorded in pounds (lbs) utilizing a “make” test. Descriptive statistics were obtained for all measures.ResultsAll data were analyzed as a single group (average age: 9.02). No significant difference in average total arc of PROM (ER+IR=Total Arc) on the D side compared to the ND side (136.7 ± 12.7 deg vs. 134.3 ± 12.3 deg). There were statistically significant differences between ER ROM (102.2 ± 7.7 deg vs. 96.8 ± 7.4 deg) and IR ROM (34.4 ± 9.0 deg vs. 37.5 ± 9.5 deg) between D versus ND arms (p= .000, .006 respectively). Mean ER strength in neutral (13.6 ± 3.4 and 12.8 ± 3.6 lbs) and 90 deg abduction (12.3 ± 3.4 and 12.5 ± 4.3 lbs) did were not significantly different between D and ND arms, respectively. Mean IR strength in neutral (18.0 ± 6.0 and 15.7 ± 4.7 lbs) and 90 deg abd (16.4 ± 5.6 and 15.0 ± 5.7 lbs) was significantly greater in the D arm vs ND arm, respectively (p=.000, .001).ConclusionThese data can provide descriptive information for clinicians who treat very young baseball players. These data show sport specific adaptations occur at very young ages (5-12) and are similar to prior reports on adolescent, high school and professional baseball players regarding upper extremity ROM and rotator cuff strength.Level of Evidence3

Shoulder injuries are frequent in rugby, and muscular deficiency and/or imbalance of the internal (IR) and external (ER) shoulder rotators are considered as probable mechanisms of shoulder injuries. The purpose of this study was to investigate whether the rotators strength imbalances occur in rugby players by comparing IR and ER strength and ER/IR ratios between rugby players (RP) and nonathletic subjects. Fourteen RP and 19 healthy nonathletic subjects were evaluated in this cross-sectional controlled study with a Con-Trex ((R)) dynamometer. IR and ER isokinetic strength were performed at 60 degrees . s (-1) and 240 degrees . s (-1) in concentric, and 60 degrees . s (-1) in eccentric, for both sides. Strength values were higher for RP than nonathletic ones ( P<0.05), but if peak torque was normalised to body weight, there were no significant differences. There was no significant effect of laterality on the IR and ER peak torque, and no significant influence of rugby and/or laterality on the ER/IR ratio. In conclusions, our results reported no rotators muscles imbalance in RP as a possible risk factor of glenohumeral injury.

The Attenuated Total Reflection Method

Surface melting and crystallization behavior of polyhydroxyalkanoates studied by attenuated total reflection infrared spectroscopy

In the course of developing EO polymers, a convenient and fast method to obtain the electrooptic (EO) coefficients, r33 and r13, is highly desirable. Some of the existing EO measurement techniques such as Fabry-Perot interferometry(1) and ellipsometry(2) require metal deposition and electrode processing for each test sample. Therefore, they are not suited for daily sample testing. Second harmonic generation (SHG) is an indirect method to measure the EO coefficients(3). It is usually performed with 1.064 Nd:YAG laser and encounters difficulties with polymers that contain high µβ chromophores because these chromophores usually have red-shifted absorption peaks that causes the Kleiman symmetry, a fundamental assumption of this technique, to break down. Attenuated total reflection (ATR) can directly measure the EO coefficients with no restriction on the wavelength of the absorption peak. One measurement scan provides the refractive index, the thickness, and an EO coefficient. Typically, the thin film electrode in contact with the test sample is made of Au or Ag in conventional ATR techniques(4). These metal thin films are soft and not durable for repeated measurements. The curve fitting algorithm for data processing(4, 5) is also inconvenient for fast sample evaluation. In this paper, a modified ATR technique for routine EO measurement is presented which does not require electrode preparation for each test sample and uses a simple algorithm for data processing.