Narrow Notch Research Articles

Bony morphologic factors affecting injury risk, rotatory stability, outcomes, and re-tear rate after anterior cruciate ligament reconstruction

A growing body of evidence has demonstrated that factors contributing to anterior cruciate ligament (ACL) injury risk are multifactorial. Recent studies have suggested that bony morphologic features play a sizeable role in this injury risk. Posterior tibial slope and posterior femoral condyle characteristics have been correlated to rotatory knee stability. Tibial slope, increased posterior femoral condylar depth, deepened lateral femoral notch, and intercondylar notch morphology have all been associated with increased ACL injury risk, and in some cases ACL reconstruction failure rates. It is crucial that surgeons understand the influence of these factors on ACL injury and their implications in ACL reconstruction. In select cases, these bony factors can be modified (e.g., osteotomy to decrease the tibial slope). In other cases, surgical, rehabilitation, and return to play strategies may need to be altered (e.g., close evaluation for lateral meniscal tears in the setting of deepened lateral femoral notch, careful graft choice and positioning in the setting of a narrow intercondylar notch). In summary, careful assessment and understanding of bony morphology is paramount to optimizing ACL reconstruction outcomes.

Anatomical Variations of the Scapula in Adult Egyptian Population and their Clinical Implication: Morphological and Morphometric Study on Dry Bone and Radiograph

Background: Knowledge of the normal anatomy and the possible variations of the scapula are beneficial in early diagnosis and proper management of shoulder disorders to evade its disabling complications as well as to avoid injury of the important neurovascular structures around the scapula.Aim of work: To estimate the prevalence of the anatomical variations of the scapula and their clinical implications and to calculate the acromion index and acromio-humeral interval; which could be helpful in the management of rotator cuff diseases.Material and Methods: One hundred dried scapulae were studied for morphological and morphometric variations. A radiological study was done by calculating both acromion index and acromio humeral interval in one hundred radiographs.Results: Four types of acromion were observed: type-1(flat), type-2(curved), type-3 (hooked) and type-4 (convex downwards). Four shapes of acromion were identified: cobra-head, triangular, rectangular and square. Acromion thickness ranged from 5 to 11mm.Acromion length ranged from 24 to 65mm.Acromion width ranged from 18 to 40mm.Acromio-glenoid distance (AGD) ranged from 20 to 40mm.Acromio-coracoid distance ranged from 22 to 68mm. Suprascapular notch shapes included U-shaped, V-shaped, J-shaped and W-shaped notch that was encountered for the first time in literature. Suprascapular notch types were: type-1 (absent notch), type-2 (wide and shallow notch), type-3 (narrow and deep notch), type-4 (a bony foramen) and Type-5 (a notch is present above a bony foramen). Anatomical variations causing snapping scapula were lushka tubercle and teres major process. Acromion index (AI) ranged from 0.63 to 0.71. Acromio-humeral interval (AHI) ranged from 7 to 14mm.Conclusion: The anatomical variations of the scapula should be considered by orthopaedicians, as it influences the technique and instrumentation in open or arthroscopic surgical procedures.

A wideband high gain dielectric resonator antenna for RF energy harvesting application

A novel high gain and broadband hybrid dielectric resonator antenna (DRA) is designed and experimentally validated. To obtain the wide impedance bandwidth, the proposed antenna geometry combines the dielectric resonator antenna and an underlying slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of the slot and DRA. An inverted T-shaped feed line is used to excite both antennas, simultaneously. It supports amalgamation of different resonant modes of the both, DRA and slot antenna. The measured results show that the proposed antenna offers an impedance bandwidth of 120% from 1.67 to 6.7GHz. The antenna gain is next enhanced by a reflector placed below the antenna at an optimum distance. On engineering the height and dimension of this reflector the antenna gain is improved from 2.2dBi to 8.7dBi at 1.7GHz. Finally, antenna operation is attested experimentally with a rectifier circuit in the frequency range of 1.8–3.6GHz, where various strong radio signals are freely available for RF energy harvesting. The measured maximum efficiency of the rectifier and rectenna circuit were found to be 74.4% and 61.4%, respectively.

Combining the crack compliance method and speckle interferometry data for determination of stress intensity factors and T-stresses

An advanced experimental technique for determination of the stress intensity factor (SIF) and the T-stress is developed and carefully verified. The approach employs optical interferometric measurements of local deformation response to small crack length increment. Narrow notches are used for crack modeling. Initial experimental data represent in-plane displacement component values measured by electronic speckle-pattern interferometry in the vicinity of the crack tip. Determination of the first four coefficients of Williams’ series is the main feature of the developed technique. Relationships for transition from measured in-plane displacement components to required fracture mechanics parameters are presented. Availability of high-quality interference fringe patterns, which are free from rigid-body motion, serves as a reliable indicator of real strain state near the crack tip. Experimental verification of the proposed method is performed for non-symmetrical and symmetrical crack in thin rectangular plates subjected to uniaxial tension. The distributions of SIF and T-stress values for cracks of different length in residual stress fields near electronically welded joints of thin plates are presented as an example of practical implementing.

Fiber-optic magnetic field sensor using a phase-shifted fiber Bragg grating assisted by a TbDyFe bar

A compact fiber-optic magnetic field sensor based on edge filtering method is proposed and experimentally demonstrated by using low-cost intensity interrogation. A phase-shifted fiber Bragg grating (PS-FBG) with two extremely narrow notches is bonded on a TbDyFe bar by epoxy resin oriented along the longitudinal direction. As the TbDyFe acts as a magnetic field transducer and PS-FBG as a strain sensor, the magnetic field strength distribution of two permanent magnets can be measured by monitoring the reflected intensity variations of the PS-FBG probe. The magnetic field sensing device shows a detection resolution of 0.023mT and a measured magnetic domain ranging from 2.43mT to 22.54mT. The reversibility and orientation-dependence of the proposed sensor are also experimentally investigated.

A Triple Band Frequency Selective Surface Design for GSM Systems by Utilizing a Novel Synthetic Resonator

In this communication, a novel triple band frequency selective surface (FSS) designed for Global System for Mobile Communications (GSMs) frequency bands is presented. Unit cell of the proposed FSS consists of one rectangular-shaped resonator designed for 942 MHz and one synthetic resonator designed for both of 1842 and 2142 MHz frequencies. A novel technique is introduced to design a synthetic resonator in which two loop-shaped resonators intersect to each other resulting a unique resonator operating at two frequencies. The proposed design has the advantages of separating two very closely spaced frequency bands as in GSM systems with a narrow notch between the two frequencies of 1842 and 2142 MHz. Furthermore, a very low-frequency response sensitivity to the oblique incidence angles is achieved by using a miniaturized single synthetic resonator for the two frequencies in a single layer. Good agreement is observed between the measured and simulated results. A minimum of 20-dB attenuation for the transmission coefficient is achieved in all downlink frequency ranges of GSM system with a good stability against the oblique angle of incidence for both transverse-electric and transverse-magnetic polarizations.

New species of Thylacocephala (Arthropoda) from the Spathian (Lower Triassic) of Chaohu, Anhui Province of China

We describe a new species of Thylacocephala, Ankitokazocaris chaohuensis sp. nov., from the Upper Spathian (Early Triassic) of Chaohu, Anhui Province, China. It is diagnosed by its unique outline of the carapace, small size, and the narrow and asymmetrical anterior notch. Fine preservation reveals at least 14 posterior appendages, traces of gills and raptorial appendages, and remains of trunk segments and muscles in Ankitokazocaris for the first time. This is the first report of Thylacocephala from the Early Triassic of China, confirming the wide distribution of this group in the Tethys. The new species is closer to the type species of Ankitokazocaris, which is stratigraphically somewhat older, than to a recently described almost coeval species from Japan.

Beak from the body chamber of an Early Carboniferous shelled longiconic coleoid cephalopod from Arkansas, USA

Here we report the discovery of an Early Carboniferous (Late Visean) 3D cephalopod beak displaying significant similarity to the lower beak of Recent coleoids. It was uncovered in a fragmentarily preserved, longiconic shell from the Moorefield Formation in Arkansas, USA. This shell comprises a fractured 29-mm-long body chamber having a maximum diameter of ~14 mm and showing an indistinct pro-ostracum-like structure. The beak-bearing shell could easily have been mistaken for a bactritid or orthocerid if it were not for a coleoid-type, weakly mineralized, evidently organic-rich shell wall which shows a lamello-columnar ultrastructure of a bulk of shell wall thickness and plate ultrastructure of thin outer layer. The specimen is assigned to an as-yet unnamed shelled coleoid of a so far unknown high-level taxonomic group. A partially exposed, 4.0-mm-long portion of the beak is the lower beak in oblique view from its left side. It exhibits fractured anthracite-like black, apparently originally chitin material, helmet-like general shape, broad hood with narrow shallow median groove and small notch posteriorly, pronounced pointed, non-biomineralized upside belt rostrum, high shoulder and about a 90–100 degrees jaw angle. A broad hood and massive rostrum emphasize its similarity to the lower mandible of Recent Vampyroteuthis and signify that its unique, among living coleoids, structure has been existed for at least since Late Visean time (~333 my).

A 16-Gb/s 14.7-mW Tri-Band Cognitive Serial Link Transmitter With Forwarded Clock to Enable PAM-16/256-QAM and Channel Response Detection

A cognitive tri-band transmitter (TX) with a forwarded clock using multiband signaling and high-order digital signal modulations is presented for serial link applications. The TX features learning an arbitrary channel response by sending a sweep of continuous wave, detecting power level at the receiver side, and then adapting modulation scheme, data bandwidth, and carrier frequencies accordingly based on detected channel information. The supported modulation scheme ranges from nonreturn to zero/Quadrature phase shift keying (QPSK) to Pulse-amplitude modulation (PAM) 16/256-Quadrature amplitude modulation(QAM). The proposed highly reconfigurable TX is capable of dealing with low-cost serial channels, such as low-cost connectors, cables, or multidrop buses with deep and narrow notches in the frequency domain (e.g., a 40-dB loss at notches). The adaptive multiband scheme mitigates equalization requirements and enhances the energy efficiency by avoiding frequency notches and utilizing the maximum available signal-to-noise ratio and channel bandwidth. The implemented TX prototype consumes a 14.7-mW power and occupies 0.016 mm2 in a 28-nm CMOS. It achieves a maximum data rate of 16 Gb/s with forwarded clock through one differential pair and the most energy efficient figure of merit of 20.4 $\mu \text{W}$ /Gb/s/dB, which is calculated based on power consumption of transmitting per gigabits per second data and simultaneously overcoming per decibel worst case channel loss within the Nyquist frequency.

The Influence of Intercondylar Notch Shape and Size on the Treatment Algorithm for Anatomic Anterior Cruciate Ligament Reconstruction

The intercondylar notch and anterior cruciate ligament (ACL) are closely related. Literature suggests that patients with a narrow intercondylar notch may be predisposed to ACL injury. However, the notch is also important during ACL reconstruction surgery. A narrow notch or A-shaped notch may make it difficult to drill the femoral tunnel from the medial portal and may not be able to accommodate a double-bundle technique. However, if these considerations are taken into account, a narrow notch does not predispose to ACL graft rupture. This article provides a historic overview of the research performed on the intercondylar notch as it related to ACL injury risk. In addition, it provides guidelines for intraoperative decision-making.

Acoustic emission sensor system using a chirped fiber-Bragg-grating Fabry–Perot interferometer and smart feedback control

We demonstrate a fiber-optic acoustic emission (AE) sensor system that is capable of performing AE detection, even when the sensor is experiencing large quasi-static strains. The sensor is a Fabry-Perot interferometer formed by cascaded chirped fiber-Bragg gratings (CFBGs). The reflection spectrum of the sensor features a number of narrow spectral notches equally spaced within the reflection bandwidth of the CFBG. A semiconductor laser whose wavelength can be fast tuned through current injection is used to lock the laser line to the center of a slope of a spectral notch. When the notch is knocked out of the tuning range of the laser, a neighboring notch moves into the range. Through a smart feedback control scheme, the laser is unlocked from the current spectral lock and relocked to the desired point of the new notch. The fast speed of the unlocking/relocking process (<1 ms) ensures that the AE signal is monitored without significant disruption.

Shape variability of the adult human acetabulum and acetabular fossa related to sex and age by geometric morphometrics. Implications for adult age estimation

This study aims to explore shape variability of the acetabulum during the human adult life span, in relation to sex and age. The human acetabular shape was analysed in 682 os coxae from three different documented skeletal collections from the Iberian Peninsula. Two landmarks and thirty-two sliding semi-landmarks were used for the geometric morphometric procedures and a clock-wise standard was used for orientation. The 180° meridian (6:00) line was positioned over the midpoint of the acetabular notch and 36 reference points in 10° increments along the rim were marked. Data showed that size, sex and age significantly influence acetabular shape variation. Sex differences were significant in individuals younger than 65 years old and were characterised by males exhibiting relatively extended acetabular rim profiles from 10:00 to 1:00, narrower acetabular notches, and reduced acetabular fossae. In addition, three main age-related changes occurred to the acetabular shape in both sexes: outer acetabular profile modification, with extension from 10:00 to 1:00 and reduction from 7:00 to 9:00, acetabular notch narrowing, and acetabular fossa reduction. The age-related changes that were observed are shared by both sexes and seem to be related to bone production associated with age. Specifically, age appears to affect the entire border of the lunate surface: the acetabular rim, both acetabular horns, and the outer edge of the acetabular fossa. Furthermore, shape data confirmed the clover-leaf shape of the acetabular fossa in both males and females. These results improve our understanding of acetabular shape, and assist in refining age-estimation methods and enhancing hip surgery and rehabilitation.

Multiple band notch and Dual-Band filter using concentric and contiguous split ring resonators (CCSRR)

A novel, compact, multiple band notch filter and dual-band filters are presented. Contiguous and concentric split ring resonators (SRRs) and Ring resonator are used to achieve desired multiple narrow band notches. These band notches have been designed to avoid the undesired interference between co-existing wireless channels. The dual-band filter consists of a dual SRR having splits on the opposite sides with Inductive Short Stub Split Ring Resonator. Even- and odd-mode analyses have been performed to calculate the resonance frequencies. Three transmission zeros are achieved between the two passbands by both dominant electric or dominant magnetic coupling and also cancellation effect of electric and magnetic coupling. This results in high passband selectivity and improved band-to-band isolation. The proposed dual-band pass filter has the advantages of being compact with more degree of freedom to achieve desired passbands by controlling the electric and magnetic coupling independently. Proposed filter is implemented on RT/Duroid 5880 (εr = 2.2) substrate of thickness 0.785 mm and surface area of 0.27λg × 0.27λg. Insertion loss of the proposed filter at notch bands is high (>13 dB) and low (<0.8 dB) in pass band. Measured results correlate with the simulated results and thus ensure that the proposed filter is a suitable candidate to mitigate interference caused by the co-existing and emerging wireless technologies.

ASSOCIATION OF ANTERIOR CRUCIATE LIGAMENT DEGENERATION WITH MEDIAL MENISCUS TEAR AND INTERCONDYLAR NOTCH IMPINGEMENT

To explore the association of anterior cruciate ligament (ACL) degeneration with intercondylar notch impingement and the medial meniscus tear in knee osteoarthritis (KOA). Between July 2014 and February 2016, 55 KOA patients (55 knees) with ACL degeneration (degeneration group) and 55 KOA patients (55 knees) without ACL degeneration (control group) were included in the study. No significant difference was found in gender, age, body mass index, and side between 2 groups (P>0.05). The notch width index was measured on preoperative MRI to evaluate whether the intercondylar notch was narrow. The location of the medial and lateral meniscus tear and osteophyte of the ACL tibial insertion were observed under arthroscopy, and the incidences of the meniscus tear and osteophyte were calculated. There was no significant difference in anterior horn and body tear of the medial meniscus and in anterior horn, body, posterior horn, and root tear of the lateral meniscus (P>0.05). Significant difference was found in the posterior horn and root tear of the medial meniscus, osteophyte of the ACL tibial insertion, narrow intercondylar notch, and the notch width index between 2 groups (P<0.05). The incidence of root tear of the medial meniscus was 53.8% (7/13) in 13 knees with osteophyte of the ACL tibial insertion and was 16.5% (16/97) in 97 knees without osteophyte, showing significant difference (χ2=9.671, P=0.002). There is a strong association of ACL degeneration with posterior horn and root tear of the medial meniscus and intercondylar notch impingement in KOA. And the high incidence of root tear of the medial meniscus in knee is correlated with osteophyte of the ACL tibial insertion.

Narrow Intercondylar Notch and Anterior Cruciate Ligament Injury in Female Nonathletes with Knee Osteoarthritis Aged 41-65 Years in Plateau Region.

Background:Few data are available concerning intercondylar notch dimensions in female nonathletes with knee osteoarthritis (OA) in plateau region. The aim of this study was to assess the relation of intercondylar notch morphology to anterior cruciate ligament (ACL) injuries in female nonathletes with knee OA aged 41–65 years from the Chinese Loess Plateau.Methods:The study was conducted on 330 patients with ACL injury (aged 31–65 years; 159 males, 171 females), 141 patients with OA (aged 31–65 years; 59 males, 82 females), and 89 female healthy controls (aged 41–65 years), and this evaluation included identifying the distribution of patients with OA or ACL injury and measuring the intercondylar notch width indexes (NWIs).Results:There was a significant rising trend in patients with OA (the Kellgren and Lawrence grade = 3) with ACL injury (OA-S + ACL) aged 41–65 years, especially in females. We found that the notches of OA-S + ACL had a smaller NWI compared with control and OA without ACL injury (OA-S-only, P = 0.000, 95% confidence interval [CI] = −0.059–−0.030; P = 0.000, 95% CI = −0.049–−0.016). A similar trend was found in notch shape index (NSI), but not in notch depth index and the cross-sectional area. The cutoff of NWI and NSI value was 0.26, and 0.65, and area under the receiver operating characteristic curve was 0.82, and 0.79, respectively. Further study displayed a significant correlation between a reduced NWI and NSI and OA-S + ACL (P = 0.000, χ2 = 14.012; P = 0.000, χ2 = 14.286).Conclusion:A narrower intercondylar notch and a plateau environment are risk factors of predisposing female nonathletes with knee OA to ACL injury aged 41–65 years.

Two new species of the genus Probles Förster (Hymenoptera: Ichneumonidae: Tersilochinae) from South Korea and Russian Far East

AbstractTwo species of the genus Probles Förster, P. interruptor sp. nov. and P. segaza sp. nov., from South Korea and Russian Far East, are described. Probles interruptor differs from its congeners by occipital carina mediodorsally narrowly interrupted and polished occipital surface extending partly on the vertex. Probles segaza differs from other species of Euporizon by its robust ovipositor with a deep and narrow dorsal subapical notch.

Compact Planar Ultrawideband Antennas With Continuously Tunable, Independent Band-Notched Filters

A compact planar ultrawideband antenna with continuously tunable, independent band notches for cognitive radio applications is presented. The antenna is fabricated using a copper-cladded substrate. A radiating patch with an inverted rectangular T-slot is etched on the top side of the substrate. A straight rectangular strip with a complete gap is embedded into the T-slot. By placing a single varactor diode across this gap, a frequency-agile band-notch function below 5 GHz is realized. On the bottom side of the substrate, a U-shaped parasitic element having an interdigitated-structure is placed beneath the radiating patch. The second narrow band notch is created by inserting a second varactor diode into the gap on one leg of the parasitic element. It has a frequency-agile performance above 5 GHz. The presence of the interdigitated structure suppresses higher order resonant modes and enhances the tunability of the notched bandwidth. Because these antenna structures naturally block dc, a very small number of lumped elements are required. The experimental results, which are in good agreement with their simulated values, demonstrate that both band notches can be independently controlled and the entire frequency-agile fractional bandwidth is as high as 74.5%, demonstrating a very wide notched frequency-agile coverage.

Experimental Investigation of Large Time–Bandwidth Product Photonic Hilbert Transformer Based on Compact Bragg Grating

We propose and experimentally demonstrate an integrated photonic Hilbert transformer (PHT) with substantial time bandwidth product (TBP). Due to the current substrate material and fabrication technique, PHT devices find it challenging to achieve ultrawide operative bandwidth while maintaining the minimum bandwidth level presented as the narrow central notch in frequency response. This implies that the TBP value is restricted. Here, we investigate the synthesized refractive index profile in compact Bragg grating design for theoretical simulation and the linearity-enhanced direct UV grating writing fabrication for experimental implementation. The fabricated device could process microwave photonic signals as Hilbert transformation between 50 GHz and 3 THz, with the TBP above 60, which is the largest experimental data to the best of our knowledge. This technique allows the PHT with improved spectral performance to be suitable for analog all-optical signal processing.

First occurrence of &amp;lt;i&amp;gt;Panthera atrox&amp;lt;/i&amp;gt; (Felidae, Pantherinae) in the Mexican state of Hidalgo and a review of the record of felids from the Pleistocene of Mexico

Abstract. Panthera atrox was a common large-sized cat in North America during the late Pleistocene. An isolated lower canine and a fifth metacarpal bone referable to this species were recovered from fluvial Quaternary deposits that outcrop in southeastern Hidalgo, central Mexico. Associated fossil material belonging to Bison indicates a Rancholabrean North American Land Mammal Age; the age assignment is corroborated by the presence of P. atrox. A comparative study with selected specimens of Panthera and Smilodon indicates that the Hidalgoan sample shares the following diagnostic features with P. atrox: a large, robust, and non-strongly curved lower canine; a large and relatively slender fifth metacarpal with a well-developed projection on the palmar side at the proximal end, narrow articulating surface for the unciform; a narrow notch on the articulating surface for the fourth metacarpal; and a diaphysis that at the middle is oval in cross section. The record supplements the evidence of P. atrox in central Mexico and represents the first reported occurrence of this cat species in the state of Hidalgo. By the same token, the known geographic distribution of P. atrox in the Mexican territory suggests that it was relatively common in temperate areas of central Mexico between 19 and 24° N at an altitudinal range from 1500 to 2250 m a.s.l. The large size (mean body mass of 300 kg) and hypercarnivorous adaptations of the American lion suggest it was the top predator of the mammalian community recorded at southeastern Hidalgo, displacing other members of the carnivore guild at the mesopredator level, such as the dire wolf (Canis dirus ), which has been also reported in the area. The high diversity of large herbivores recorded at southeastern Hidalgo, which in turn could represent potential prey of P. atrox, suggests that some areas that now are part of central Mexico were suitable hunting sites for this large-sized cat. A review of the Pleistocene record of Felidae from Mexico revealed that it encompasses 87.5 and 73.3 % of generic and specific diversity known for North America, respectively, including seven genera (Felis, Miracinonyx, Panthera, Puma, Lynx, Leopardus, and Smilodon) and 11 species (Felis rexroadensis, Miracinonyx inexpectatus, Panthera atrox, Panthera onca, Puma concolor, Puma yagouaroundi, Lynx rufus, Leopardus pardalis, Leopardus wiedii, Smilodon fatalis, and Smilodon gracilis). The majority of these taxa have been reported from numerous late Pleistocene localities; in particular, Panthera atrox was relatively common and widely distributed across the Mexican territory.

Influence of the Anisotropy of Materials on the Distribution of Stresses Near Parabolic Notches

We consider the problems of distribution of stresses in an infinite anisotropic plane containing a parabolic notch for three main types of deformation in the case where the asymptotics of the stress field is specified at infinity (including stress intensity factors at the tip of the corresponding semiinfinite crack). The solutions of these problems are obtained with the help of the limit transition from the known analytic solutions obtained for an elliptic hole in the anisotropic plane for three types of loading at infinity (symmetric tension, transverse and longitudinal shear). These results generalize the well-known data on the distribution of stresses near narrow rounded notches in the isotropic plane and reflect the influence of anisotropy of the material on the stress concentration.