Arthroscopic Medialization Partial Repair with Biologic Interposition Tuberoplasty for Large to Massive Irreparable Rotator Cuff Tear.

An irreparable rotator cuff tear is a challenging condition to treat, and various treatment modalities are being introduced. Medialization in the partial repair method has the limitation of exposing the tuberosity, while tension-free biologic interposition tuberoplasty using acellular dermal matrix has the limitation of exposing the humeral head. The authors believe that by combining these two techniques, it is possible to complement each other's limitations. Therefore, they propose a surgical method that combines medialization and biologic interposition tuberoplasty for addressing these constraints.

Combination of arthroscopic biologic tuberoplasty and bursal acromial reconstruction.

Background: Recently, among the various method for irreparable rotator cuff tears, the "tension-free allodermis graft technique" has been introduced as a method for arthroscopic biologic tuberoplasty(ABT) and bursal acromial reconstruction(BAR).The objective was to analyze the outcomes of ABT and BAR combination surgical technique. Methods: Eighteen cases who underwent simultaneous ABT and BAR procedures were retrospectively recruited. Before the surgery and at one year post-surgery, the researchers assessed the patients' Visual Analog Scale(VAS), American Shoulder and Elbow Surgeons(ASES) scores, pain scores, range of motion(ROM), retear, and acromiohumeral distance (AHD). Results: One year post-surgery, both the VAS pain scores, ASES scores, and ROM showed statistically significant improvement compared to before the surgery. Upon reviewing the radiological results, the AHD significantly improved from 4.3 ± 4.1 mm before surgery to 9.2 ± 1.9 mm at one year post-surgery (p < 0.001). Moreover, in the one year follow-up, there was no observed failure of the allodermis graft in any of the cases. Conclusion: The combination of ABT and BAR demonstrated significantly improved clinical outcomes after surgery, showing a substantial increase in AHD and preventing graft failure effectively.

Rationally Designed TiO2 Nanostructures of Continuous Pore Network for Fast-Responding and Highly Sensitive Acetone Sensor.

For the last several years, indoor air quality monitoring has been a significant issue due to the increasing time portion of indoor human activities. Especially, the early detection of volatile organic compounds potentially harmful to the human body by the prolonged exposure is the primary concern for public human health, and such technology is imperatively desired. In this study, highly porous and periodic 3D TiO2 nanostructures are designed and studied for this concern. Specifically, extremely high gas molecule accessibility throughout the whole nanostructures and precisely controlled internecks of 3D TiO2 nanostructures can achieve an unprecedented gas response of 299 to 50 ppm CH3 COCH3 with an extremely fast response time of less than 1s. The systematic approach to utilize the whole inner and outer surfaces of the gas sensing materials and periodically formed internecks to localize the current paths in this study can provide highly promising perspectives to advance the development of chemoresistive gas sensors using metal oxide nanostructures for the Internet of Everything application.

Arthroscopic treatment of iliopsoas tendinitis after total hip arthroplasty with acetabular cup malposition: Two case reports.

BACKGROUND: Optimal treatment for iliopsoas tendinitis after total hip arthroplasty (THA) with cup malposition, iliopsoas release alone or with cup revision, is controversial, particularly in young, active patients. Moreover, arthroscopic iliopsoas tendon (IPT) release in these patients has been rarely described, and midterm effects of this procedure on THA longevity and groin pain recurrence remain unclear. We performed arthroscopic IPT release after THA and report midterm outcomes in two young patients with acetabular cup malposition. CASE SUMMARY: In the two patients, groin pain started early after THA. Physical examination revealed nonspecific findings, and laboratory tests showed no evidence of infection. Radiography and computed tomography showed reduced acetabular component anteversion angle and anterior cup prominence of more than 16 mm. For therapeutic diagnosis, ultrasonography-guided lidocaine with steroid was injected into the IPT sheath. In both patients, groin pain improved initially but worsened after a few months. Therefore, the patients underwent arthroscopic IPT release under spinal anesthesia. Arthroscopy revealed synovitis with fibrous tissues around the IPT and various lesions related to the implants after THA. IPT tenotomy and debridement with biopsy were performed; histopathologic studies showed chronic inflammation with synovial hyperplasia. Both patients were encouraged to start walking immediately after surgery, and they returned to complete daily function early after surgery. They experienced no recurrence of groin pain or any implant-related problems 5 years postoperatively. CONCLUSION: Arthroscopic IPT release for cup malposition produced excellent midterm outcomes without recurrence of groin pain and implant-related problems.

Focused Electric-Field Polymer Writing: Toward Ultralarge, Multistimuli-Responsive Membranes.

The cost-effective direct writing of polymer nanofibers (NFs) has garnered considerable research attention as a compelling one-pot strategy for obtaining key building blocks of electrochemical and optical devices. Among the promising applications, the changes in optical response from external stimuli such as mechanical deformation and changes in the thermal environment are of great significance for emerging applications in smart windows, privacy protection, aesthetics, artificial skin, and camouflage. Herein, we propose a rational design for the mass production of customized NFs through the development of focused electric-field polymer writing (FEPW) coupled with the roll-to-roll technique. As a proof of key applications, we demonstrate multistimuli-responsive (mechano- and thermochromism) membranes with an exceptional production scale (over 300 cm2). Specifically, the membranes consist of periodically aligned ultrathin (∼60 nm) alumina nanotubes inserted in the elastomers. We performed a two-phase finite element analysis of the unit cells to verify the underlying physics of light scattering at heterogeneous interfaces of the strain-induced air gaps. By adding thermochromic dye during the FEPW, the optical modulation of transmittance change (∼83% to 37% at visible wavelength) was successfully extended to high-contrast thermal-dependent coloration.

High-Contrast Optical Modulation from Strain-Induced Nanogaps at 3D Heterogeneous Interfaces.

The realization of high-contrast modulation in optically transparent media is of great significance for emerging mechano-responsive smart windows. However, no study has provided fundamental strategies for maximizing light scattering during mechanical deformations. Here, a new type of 3D nanocomposite film consisting of an ultrathin (≈60 nm) Al2O3 nanoshell inserted between the elastomers in a periodic 3D nanonetwork is proposed. Regardless of the stretching direction, numerous light-scattering nanogaps (corresponding to the porosity of up to ≈37.4 vol%) form at the interfaces of Al2O3 and the elastomers under stretching. This results in the gradual modulation of transmission from ≈90% to 16% at visible wavelengths and does not degrade with repeated stretching/releasing over more than 10 000 cycles. The underlying physics is precisely predicted by finite element analysis of the unit cells. As a proof of concept, a mobile-app-enabled smart window device for Internet of Things applications is realized using the proposed 3D nanocomposite with successful expansion to the 3 × 3 in. scale.

Experimental and Numerical Investigations of High-Speed Projectile Impacts on 7075-T651 Aluminum Plates.

Simulation of the material failure under high strain rate conditions is one of the most difficult problems in the finite element analyses, and many researchers have tried to understand and reproduce dynamic material fracture. In this study, we investigate a failure criterion that minimizes the mesh dependency at high strain rates and incorporates the criterion into the Johnson-Cook constitutive relationship by developing a user-defined material model. Impact tests were performed using a gas-gun system in order to investigate the response of the 7075-T651 aluminum plate in high-speed collision. On the other hand, numerical simulations are carried out by considering various element sizes and the relationship between element size and failure strain is inversely obtained using numerical results. By accommodating the relationship into the damage model and implementing in the user-defined material model, mesh dependency is significantly reduced, and sufficient accuracy is achieved with alleviated computational cost than the existing damage model. This study suggests an element size-dependent damage criterion that is applicable for impact simulation and it is expected that the criterion is useful to obtain accurate impact responses with a small computational cost.

Comparing the effect between continuous infusion and intermittent bolus of rocuronium for intraoperative neurophysiologic monitoring of neurointervention under general anesthesia.

BACKGROUND: Medical researchers have been reluctant to use neuromuscular blocking drugs (NMBD) during the use of intraoperative motor evoked potential (MEP) monitoring despite the possibility of patient movement. In this study, we compared the effects of no NMBD and continuous rocuronium infusion on the incidence of patient involuntary movement and MEP monitoring. METHODS: In this study, 80 patients who underwent neuro intervention with MEP monitoring were randomly assigned into 2 groups. After an anesthetic induction, bolus of rocuronium 0.1 mg/kg was injected when it was needed (for patient involuntary movement or at the request of the surgeon) in group B, and 5 mcg/kg/min of rocuronium were infused in group I study participants. The incidence of patient involuntary movement and spontaneous respiration, the mean MEP amplitude, coefficient of variation (CV), the incidence of MEP stimulus change and train-of-four (TOF) count were compared. RESULTS: The incidence of involuntary movement and spontaneous movement were measured as significantly lower in group I (P < .05). The incidence of undetectable MEP did not differ as measured in both groups. The means and CVs of MEP amplitude in all limbs were significantly lower in group I. The mean TOF counts from 30 to 80 min of operation were significantly higher in group B. CONCLUSION: We conclude that the continuous infusion of rocuronium effectively inhibited the involuntary movement and spontaneous respiration of the patient while enabling MEP monitoring.

Multifunctional Polymer Nanocomposites Reinforced by 3D Continuous Ceramic Nanofillers.

Polymer nanocomposites with inclusion of ceramic nanofillers have relatively high yield strength, elastic moduli, and toughness that therefore are widely used as functional coating and films for optoelectronic applications. Although the mechanical properties are enhanced with increasing the fraction of nanofiller inclusion, there generally is an upper limit on the amount of nanofiller inclusion because the aggregation of the fillers in the polymer matrix, which typically occurs, degrades the mechanical and/or optical performances above 5 vol % of inclusions. Here, we demonstrate an unconventional polymer nanocomposite composed of a uniformly distributed three-dimensional (3D) continuous ceramic nanofillers, which allows for extremely high loading (∼19 vol %) in the polymer matrix without any concern of aggregation and loss in transparency. The fabrication strategy involves conformal deposition of Al2O3 nanolayer with a precise control in thickness that ranges from 12 to 84 nm on a 3D nanostructured porous polymer matrix followed by filling the pores with the same type of polymer. The 3D continuous Al2O3 nanolayers embedded in the matrix with extremely high filler rate of 19.17 vol % improve compressive strength by 142% compared to the pure epoxy without Al2O3 filler, and this value is in agreement with theoretically predicted strength through the rule of mixture. These 3D nanocomposites show superb transparency in the visible (>85% at 600 nm) and near-IR (>90% at 1 µm) regions and improved heat dissipation beyond that of conventional Al2O3 dispersed nanocomposites with similar filler loading of 15.11 vol % due to the existence of a continuous thermal conduction path through the oxide network.

Sacral epiduroscopic laser decompression for complex regional pain syndrome after lumbar spinal surgery: A case report.

RATIONALE: CRPS after a lumbar surgery has symptoms that are similar to PSSS. However, standard criteria for distinguishing CRPS from PSSS do not exist. We present a case report of a 31-year-old female with CRPS symptoms after lumbar spinal surgery treated by performing SELD. PATIENT CONCERNS: This patient was referred to our pain clinic for left ankle pain. She received a lumbar discectomy for a herniated lumbar disc (L5/S1) but the pain was aggravated after surgery. DIAGNOSES: The characteristics of the pain were burning, tingling, and cold, and were accompanied by other symptoms such as swelling, color change and mail dystrophy. The patient was diagnosed with CRPS. INTERVENTIONS: Medications and interventional therapies were not effective in reducing pain. SELD was performed and severe adhesive inflammation was observed in the L4-S1 epidural space. We performed mechanical adhesiolysis and injected hyalurodinase and dexamethasone near the L5 and S1 root. One month after, a second SELD was performed as same manner. OUTCOMES: After second SELD, the patient's pain markedly decreased. On the second visit in the outpatient clinic, the patient was absent of pain without any other medications. LESSONS: CRPS like symptoms can appear after lumbar spinal surgery due to adhesion and inflammation in the epidural space. In such cases, SELD can be considered as diagnostic and therapeutic option.

An improved anonymous authentication scheme for roaming in ubiquitous networks.

With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people's lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.'s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al's scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments.

Security analysis and enhanced user authentication in proxy mobile IPv6 networks.

The Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management protocol that allows a Mobile Node(MN) connected to the PMIPv6 domain to move from one network to another without changing the assigned IPv6 address. The user authentication procedure in this protocol is not standardized, but many smartcard based authentication schemes have been proposed. Recently, Alizadeh et al. proposed an authentication scheme for the PMIPv6. However, it could allow an attacker to derive an encryption key that must be securely shared between MN and the Mobile Access Gate(MAG). As a result, outsider adversary can derive MN's identity, password and session key. In this paper, we analyze Alizadeh et al.'s scheme regarding security and propose an enhanced authentication scheme that uses a dynamic identity to satisfy anonymity. Furthermore, we use BAN logic to show that our scheme can successfully generate and communicate with the inter-entity session key.

Implicit Regularization for Reconstructing 3D Building Rooftop Models Using Airborne LiDAR Data.

With rapid urbanization, highly accurate and semantically rich virtualization of building assets in 3D become more critical for supporting various applications, including urban planning, emergency response and location-based services. Many research efforts have been conducted to automatically reconstruct building models at city-scale from remotely sensed data. However, developing a fully-automated photogrammetric computer vision system enabling the massive generation of highly accurate building models still remains a challenging task. One the most challenging task for 3D building model reconstruction is to regularize the noises introduced in the boundary of building object retrieved from a raw data with lack of knowledge on its true shape. This paper proposes a data-driven modeling approach to reconstruct 3D rooftop models at city-scale from airborne laser scanning (ALS) data. The focus of the proposed method is to implicitly derive the shape regularity of 3D building rooftops from given noisy information of building boundary in a progressive manner. This study covers a full chain of 3D building modeling from low level processing to realistic 3D building rooftop modeling. In the element clustering step, building-labeled point clouds are clustered into homogeneous groups by applying height similarity and plane similarity. Based on segmented clusters, linear modeling cues including outer boundaries, intersection lines, and step lines are extracted. Topology elements among the modeling cues are recovered by the Binary Space Partitioning (BSP) technique. The regularity of the building rooftop model is achieved by an implicit regularization process in the framework of Minimum Description Length (MDL) combined with Hypothesize and Test (HAT). The parameters governing the MDL optimization are automatically estimated based on Min-Max optimization and Entropy-based weighting method. The performance of the proposed method is tested over the International Society for Photogrammetry and Remote Sensing (ISPRS) benchmark datasets. The results show that the proposed method can robustly produce accurate regularized 3D building rooftop models.

Efficient and Security Enhanced Anonymous Authentication with Key Agreement Scheme in Wireless Sensor Networks.

At present, users can utilize an authenticated key agreement protocol in a Wireless Sensor Network (WSN) to securely obtain desired information, and numerous studies have investigated authentication techniques to construct efficient, robust WSNs. Chang et al. recently presented an authenticated key agreement mechanism for WSNs and claimed that their authentication mechanism can both prevent various types of attacks, as well as preserve security properties. However, we have discovered that Chang et al's method possesses some security weaknesses. First, their mechanism cannot guarantee protection against a password guessing attack, user impersonation attack or session key compromise. Second, the mechanism results in a high load on the gateway node because the gateway node should always maintain the verifier tables. Third, there is no session key verification process in the authentication phase. To this end, we describe how the previously-stated weaknesses occur and propose a security-enhanced version for WSNs. We present a detailed analysis of the security and performance of our authenticated key agreement mechanism, which not only enhances security compared to that of related schemes, but also takes efficiency into consideration.

Staged minimally invasive plate osteosynthesis of proximal tibial fractures with acute compartment syndrome.

PURPOSE: High-energy proximal tibial fractures often accompany compartment syndrome and are usually treated by fasciotomy with external fixation followed by secondary plating. However, the initial soft tissue injury may affect bony union, the fasciotomy incision or external fixator pin sites may lead to postoperative wound infections, and the staged procedure itself may adversely affect lower limb function. We assess the results of staged minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures with acute compartment syndrome. METHODS: Twenty-eight patients with proximal tibial fractures accompanied by acute compartment syndrome who underwent staged MIPO and had a minimum of 12 months follow-up were enrolled. According to the AO/OTA classification, 6 were 41-A, 15 were 41-C, 2 were 42-A and 5 were 42-C fractures; this included 6 cases of open fractures. Immediate fasciotomy was performed once compartment syndrome was diagnosed and stabilization of the fracture followed using external fixation. After the soft tissue condition normalized, internal conversion with MIPO was done on an average of 37 days (range, 9-158) after index trauma. At the time of internal conversion, the external fixator pin site grades were 0 in 3 cases, 1 in 12 cases, 2 in 10 cases and 3 in 3 cases, as described by Dahl. Radiographic assessment of bony union and alignment and a functional assessment using the Knee Society Score and American Orthopedic Foot and Ankle Society (AOFAS) score were carried out. RESULTS: Twenty-six cases achieved primary bony union at an average of 18.5 weeks. Two cases of nonunion healed after autogenous bone grafting. The mean Knee Society Score and the AOFAS score were 95 and 95.3 respectively, at last follow-up. Complications included 1 case of osteomyelitis in a patient with a grade IIIC open fracture and 1 case of malunion caused by delayed MIPO due to poor wound conditions. Duration of external fixation and the external fixator pin site grade were not related to the occurrence of infection. CONCLUSIONS: Staged MIPO for proximal tibial fractures with acute compartment syndrome may achieve satisfactory bony union and functional results, while decreasing deep infections and soft tissue complications.

An Improved and Secure Anonymous Biometric-Based User Authentication with Key Agreement Scheme for the Integrated EPR Information System.

Nowadays, many hospitals and medical institutes employ an authentication protocol within electronic patient records (EPR) services in order to provide protected electronic transactions in e-medicine systems. In order to establish efficient and robust health care services, numerous studies have been carried out on authentication protocols. Recently, Li et al. proposed a user authenticated key agreement scheme according to EPR information systems, arguing that their scheme is able to resist various types of attacks and preserve diverse security properties. However, this scheme possesses critical vulnerabilities. First, the scheme cannot prevent off-line password guessing attacks and server spoofing attack, and cannot preserve user identity. Second, there is no password verification process with the failure to identify the correct password at the beginning of the login phase. Third, the mechanism of password change is incompetent, in that it induces inefficient communication in communicating with the server to change a user password. Therefore, we suggest an upgraded version of the user authenticated key agreement scheme that provides enhanced security. Our security and performance analysis shows that compared to other related schemes, our scheme not only improves the security level, but also ensures efficiency.

The timing of administration of intravenous dexmedetomidine during lower limb surgery: a randomized controlled trial.

BACKGROUND: Dexmedetomidine, a selective alpha-2 agonist, has sedative, analgesic, and anxiolytic effects without respiratory depression. Dexmedetomidine can cause a biphasic cardiovascular response, and induce transient hypertension. Hypotension is a common complication of spinal anesthesia. Decreasing anxiety of patients before procedure is important for high quality of procedure. This study aimed to compare the incidence of hypotension and patients' anxiety and comfort levels when dexmedetomidine was intravenously administered before and after spinal anesthesia. METHODS: Seventy-four patients with American Society of Anesthesiologists physical status classification I or II were randomly allocated into two groups. Spinal anesthesia was performed using 12 mg of 0.5% heavy bupivacaine. In Group A, 1 µg/kg of dexmedetomidine was intravenously administered for 10 min, followed by the maintenance infusion of dexmedetomidine 0.2 µg/kg/hr after 5 min of intrathecal bupivacaine injection. Patients in Group B received same dose of dexmedetomidine by intravenous administration before 5 min of intrathecal bupivacaine injection. Perioperative vital signs, anxiety (using the Spielberger's State-Trait Anxiety Inventory) and comfort (using the numerical rating scale) were evaluated. RESULTS: The incidence of hypotension was significantly lower in Group A (16.1%) than in Group B (48.4%) during infusion of dexmedetomidine (p = 0.01). The need for treatment of hypotension is higher in Group B than Group A (p = 0.02). The incidence of bradycardia and desaturation did not significantly differ between the two groups. There were no statistically significant differences regarding the patients' anxiety and comfort. CONCLUSIONS: Hypotension is more frequently occurred, and the treatment of hypotension is more needed in Group B. The intravenously administration of dexmedetomidine before spinal anesthesia has no advantages in hemodynamic status and patients' comfort compared to that after spinal anesthesia during lower limb surgery. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT02155010 . Retrospectively registered on May 22, 2014.

Cardiac arrest after sugammadex administration in a patient with variant angina: a case report.

A 76-year-old man with no notable medical history was scheduled for a robot-assisted radical prostatectomy. After the operation, he was given sugammadex. Two minutes later, ventricular premature contraction bigeminy began, followed by cardiac arrest. Cardiac arrest occurred three times and cardiopulmonary resuscitation was done. The patient recovered after the third cardiopulmonary resuscitation and was transferred to the intensive care unit. Coronary angiography was done on postoperative day 1. The patient was diagnosed with variant angina and discharged uneventfully on postoperative day 8.

An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks.

In wireless sensor networks (WSNs), a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.'s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.'s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes.

Matching Aerial Images to 3D Building Models Using Context-Based Geometric Hashing.

A city is a dynamic entity, which environment is continuously changing over time. Accordingly, its virtual city models also need to be regularly updated to support accurate model-based decisions for various applications, including urban planning, emergency response and autonomous navigation. A concept of continuous city modeling is to progressively reconstruct city models by accommodating their changes recognized in spatio-temporal domain, while preserving unchanged structures. A first critical step for continuous city modeling is to coherently register remotely sensed data taken at different epochs with existing building models. This paper presents a new model-to-image registration method using a context-based geometric hashing (CGH) method to align a single image with existing 3D building models. This model-to-image registration process consists of three steps: (1) feature extraction; (2) similarity measure; and matching, and (3) estimating exterior orientation parameters (EOPs) of a single image. For feature extraction, we propose two types of matching cues: edged corner features representing the saliency of building corner points with associated edges, and contextual relations among the edged corner features within an individual roof. A set of matched corners are found with given proximity measure through geometric hashing, and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on collinearity equations. The result shows that acceptable accuracy of EOPs of a single image can be achievable using the proposed registration approach as an alternative to a labor-intensive manual registration process.