Open reduction and tunneled suspensory fixation for lateral end of clavicle fractures: surgical technique

Unstable distal end clavicle fractures are associated with significant rates of nonunion and poor functional outcomes. Surgical treatment is paramount for unstable fracture patterns; however, treatment options are various, with each having its advantages and drawbacks. Recently, suture-based coracoclavicular fixation techniques using suture buttons have been implemented with high union rates, satisfactory shoulder function, and low rates of complications. In this report, we demonstrate a modified fixation of unstable lateral clavicle fractures. Our technique entails open reduction and suspensory coracoclavicular fixation using suture anchors and suture button devices with supplemental acromioclavicular suspensory fixation.

Stabilization of lithium anode with ceramic-rich interlayer for all solid-state batteries

The deposition of thin layers of polymer/ceramic on a lithium surface to produce a strong barrier against dendrites was demonstrated. Different forms (needle, sphere, rod) and types of ceramic (Al₂O₃, Mg₂B₂O₅) were tested and polymer/ceramic interlayers of a few micrometers (4 μm minimum) between the lithium and the PEO-based solid polymer electrolyte (SPE) were deposited. Interlayers with high amounts of ceramic up to 85 wt% were successfully coated on the surface of lithium foil. Compact “polymer in ceramic” layers were observed when Al₂O₃ spheres were used for instance, providing a strong barrier against the progression of dendrites as well as a buffer layer to alleviate the lithium deformation during stripping/plating cycles. The electrochemical performance of the lithium anodes was assessed in symmetrical Li/SPE/Li cells and in full all-solid-state LiFePO₄ (LFP)/SPE/Li batteries. It was observed for all the cells that the charge transfer resistance was significantly reduced after the deposition of the polymer/ceramic layers on the lithium surface. In addition, the symmetrical cells were able to cycle at higher C-rates and the durability at C/4 was even improved by a factor of 8. Microscopic observations of Li/SPE/Li stacks after cycling revealed that the polymer/ceramic interlayer reduces the deformation of lithium upon cycling and avoids the formation of dendrites. Finally, LFP/SPE/Li batteries were cycled and better coulombic efficiencies as well as capacity retentions were obtained with the modified lithium electrodes. This work is patent-pending (WO2021/159209A1).

Significant electrochemical performance improvement of symmetric Li/Li polymer cells at C/4 by using ceramic-rich coated lithium anodes.

Behavior of Solid Electrolyte in Li-Polymer Battery with NMC Cathode via in-Situ Scanning Electron Microscopy

We present the first results of in situ scanning electron microscopy (SEM) of an all-solid Li battery with a nickel-manganese-cobalt-oxide (NMC-622) cathode at 50 °C and an operating voltage of 2.7-4.3 V. Experiments were conducted under a constant current at several C rates (nC rate: cycling in 1/n h): C/12, C/6, and C/3. The microstructure evolution during cycling was monitored by continuous secondary electron imaging. We found that the chemical degradation of the solid polymer electrolyte (SPE) was the main mechanism for battery failure. This degradation was observed in the form of a gradual thinning of the SPE as a function of cycling time, resulting in gas generation from the cell. We also present various dynamic electrochemical and mechanical phenomena, as observed by SEM images, and compare the performance of this battery with that of an all-solid Li battery with a LiFePO₄ cathode.

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

High-Capacity and Long-Cycle Life Aqueous Rechargeable Lithium-Ion Battery with the FePO4 Anode

Aqueous lithium-ion batteries are emerging as strong candidates for a great variety of energy storage applications because of their low cost, high-rate capability, and high safety. Exciting progress has been made in the search for anode materials with high capacity, low toxicity, and high conductivity; yet, most of the anode materials, because of their low equilibrium voltages, facilitate hydrogen evolution. Here, we show the application of olivine FePO₄ and amorphous FePO₄·2H₂O as anode materials for aqueous lithium-ion batteries. Their capacities reached 163 and 82 mA h/g at a current rate of 0.2 C, respectively. The full cell with an amorphous FePO₄·2H₂O anode maintained 92% capacity after 500 cycles at a current rate of 0.2 C. The acidic aqueous electrolyte in the full cells prevented cathodic oxygen evolution, while the higher equilibrium voltage of FePO₄ avoided hydrogen evolution as well, making them highly stable. A combination of in situ X-ray diffraction analyses and computational studies revealed that olivine FePO₄ still has the biphase reaction in the aqueous electrolyte and that the intercalation pathways in FePO₄·2H₂O form a 2-D mesh. The low cost, high safety, and outstanding electrochemical performance make the full cells with olivine or amorphous hydrated FePO₄ anodes commercially viable configurations for aqueous lithium-ion batteries.

Light-assisted delithiation of lithium iron phosphate nanocrystals towards photo-rechargeable lithium ion batteries

Recently, intensive efforts are dedicated to convert and store the solar energy in a single device. Herein, dye-synthesized solar cell technology is combined with lithium-ion materials to investigate light-assisted battery charging. In particular we report the direct photo-oxidation of lithium iron phosphate nanocrystals in the presence of a dye as a hybrid photo-cathode in a two-electrode system, with lithium metal as anode and lithium hexafluorophosphate in carbonate-based electrolyte; a configuration corresponding to lithium ion battery charging. Dye-sensitization generates electron-hole pairs with the holes aiding the delithiation of lithium iron phosphate at the cathode and electrons utilized in the formation of a solid electrolyte interface at the anode via oxygen reduction. Lithium iron phosphate acts effectively as a reversible redox agent for the regeneration of the dye. Our findings provide possibilities in advancing the design principles for photo-rechargeable lithium ion batteries.

Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy

Operando pair distribution function (PDF) analysis and ex situ (23)Na magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from (23)Na ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electrochemically; a-Na(3-x)Sb (x ≈ 0.4-0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na(1.7)Sb, a highly amorphous structure featuring some Sb-Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na(3-x)Sb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphous network reacts at higher voltages reforming a-Na(1.7)Sb, then a-Na(3-x)Sb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na(3-x)Sb without the formation of a-Na(1.7)Sb. a-Na(3-x)Sb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature (23)Na NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes.

In situ PDF and solid-state NMR studies of antimony anodes for Na-ion batteries

Sodium-ion batteries have attracted attention in recent years because of the natural abundance of sodium compared to lithium, making them particularly attractive in applications such as large-scale grid storage where low cost and sustainability, rather than light weight is the key issue [1]. Several materials have been suggested as cathodes but far fewer studies have been done on anode materials and, because of the reluctance of sodium to intercalate into graphite, the anode material of choice in commercial lithium-ion batteries, the anode represents a significant challenge to this technology. Materials which form alloys with sodium, particularly tin and antimony, have been suggested as anode materials; their ability to react with multiple sodium ions per metal-atom give potential for high gravimetric capacities[2]. However, relatively little is known about the reaction mechanism in the battery, primarily due to drastic reduction in crystallinity during (dis)charging conditions, but also because the structures formed on electrochemical cycling may not be alloys known to exist under ambient conditions. In this study, we present a study of antimony as an anode in sodium-ion batteries, using in situ pair distribution function (PDF) analysis combined with ex situ solid-state nuclear magnetic resonance studies. PDF experiments were performed at 11-ID-B, APS using the AMPIX electrochemical cell [3], cycling against sodium metal. Inclusion of diffuse scattering in analysis is able to circumvent some of the issues of crystallinity loss, and gain information about the local structure in all regions, independent of the presence of long-range order in the material. This approach has been used to probe local correlations in previously uncharacterised regions of the electrochemical profile and analyse phase progression over the full charge cycle. This analysis has been linked with ex situ 23Na solid-state NMR experiments to examine the local environment of the sodium; these show evidence of known NaxSb phases but indicate additional metastable phases may be present at partial discharge.

Algorithms and Applications for the Same-Decision Probability

When making decisions under uncertainty, the optimal choices are often difficult to discern, especially if not enough information has been gathered. Two key questions in this regard relate to whether one should stop the information gathering process and commit to a decision (stopping criterion), and if not, what information to gather next (selection criterion). In this paper, we show that the recently introduced notion, Same-Decision Probability (SDP), can be useful as both a stopping and a selection criterion, as it can provide additional insight and allow for robust decision making in a variety of scenarios. This query has been shown to be highly intractable, being PP^PP-complete, and is exemplary of a class of queries which correspond to the computation of certain expectations. We propose the first exact algorithm for computing the SDP, and demonstrate its effectiveness on several real and synthetic networks. Finally, we present new complexity results, such as the complexity of computing the SDP on models with a Naive Bayes structure. Additionally, we prove that computing the non-myopic value of information is complete for the same complexity class as computing the SDP.

Rheology of polymer solutions using colloidal-probe atomic force microscopy

We use colloidal-probe atomic force microscope (AFM) to study the rheological behavior of polymer solutions confined between two surfaces: the surface of a sphere and a flat surface on which the fluid is deposited. Measurements of the hydrodynamic force exerted on the sphere by the flowing liquid allowed retrieving the viscosity of the solution for different distances between the sphere and the flat surface. This method has been experimentally tested for Newtonian fluids for which the viscosity does not vary versus the gap dimensions. On the other hand, for non-Newtonian fluids, such as the large molecular weight polymer solutions used here, the measured viscosity depends on the gap height D between the flat surface and the sphere. The decrease of the viscosity versus gap height is similar to previously observed variations in colloidal suspensions. Depletion of polymers in the gap region due to the high shear rates involved is a possible cause for such a variation.

Outbreak of staphylococcal bullous impetigo in a maternity ward linked to an asymptomatic healthcare worker

An outbreak of staphylococcal bullous impetigo occurred over a period of five months in a maternity ward involving seven infected and two colonised neonates. The skin lesions were due to epidermolytic toxin A-producing Staphylococcus aureus. Infection control measures were implemented and a retrospective case-control study performed. Contact with an auxiliary nurse was the only risk factor for cases of bullous impetigo (P<0.01). The nurse cared for all seven cases and was an asymptomatic nasal carrier of the epidemic strain. Repeated courses of decontamination treatment failed to eradicate carriage. Nine months after the last case, another neonate developed a more severe form of bullous impetigo and the auxiliary nurse was reassigned to an adult ward.

The Language of Search

This paper is concerned with a class of algorithms that perform exhaustive search on propositional knowledge bases. We show that each of these algorithms defines and generates a propositional language. Specifically, we show that the trace of a search can be interpreted as a combinational circuit, and a search algorithm then defines a propositional language consisting of circuits that are generated across all possible executions of the algorithm. In particular, we show that several versions of exhaustive DPLL search correspond to such well-known languages as FBDD, OBDD, and a precisely-defined subset of d-DNNF. By thus mapping search algorithms to propositional languages, we provide a uniform and practical framework in which successful search techniques can be harnessed for compilation of knowledge into various languages of interest, and a new methodology whereby the power and limitations of search algorithms can be understood by looking up the tractability and succinctness of the corresponding propositional languages.

Complexity Results and Approximation Strategies for MAP Explanations

MAP is the problem of finding a most probable instantiation of a set of variables given evidence. MAP has always been perceived to be significantly harder than the related problems of computing the probability of a variable instantiation Pr, or the problem of computing the most probable explanation (MPE). This paper investigates the complexity of MAP in Bayesian networks. Specifically, we show that MAP is complete for NP^PP and provide further negative complexity results for algorithms based on variable elimination. We also show that MAP remains hard even when MPE and Pr become easy. For example, we show that MAP is NP-complete when the networks are restricted to polytrees, and even then can not be effectively approximated. Given the difficulty of computing MAP exactly, and the difficulty of approximating MAP while providing useful guarantees on the resulting approximation, we investigate best effort approximations. We introduce a generic MAP approximation framework. We provide two instantiations of the framework; one for networks which are amenable to exact inference Pr, and one for networks for which even exact inference is too hard. This allows MAP approximation on networks that are too complex to even exactly solve the easier problems, Pr and MPE. Experimental results indicate that using these approximation algorithms provides much better solutions than standard techniques, and provide accurate MAP estimates in many cases.

A Knowledge Compilation Map

We propose a perspective on knowledge compilation which calls for analyzing different compilation approaches according to two key dimensions: the succinctness of the target compilation language, and the class of queries and transformations that the language supports in polytime. We then provide a knowledge compilation map, which analyzes a large number of existing target compilation languages according to their succinctness and their polytime transformations and queries. We argue that such analysis is necessary for placing new compilation approaches within the context of existing ones. We also go beyond classical, flat target compilation languages based on CNF and DNF, and consider a richer, nested class based on directed acyclic graphs (such as OBDDs), which we show to include a relatively large number of target compilation languages.

When do Numbers Really Matter?

Common wisdom has it that small distinctions in the probabilities (parameters) quantifying a belief network do not matter much for the results of probabilistic queries. Yet, one can develop realistic scenarios under which small variations in network parameters can lead to significant changes in computed queries. A pending theoretical question is then to analytically characterize parameter changes that do or do not matter. In this paper, we study the sensitivity of probabilistic queries to changes in network parameters and prove some tight bounds on the impact that such parameters can have on queries. Our analytic results pinpoint some interesting situations under which parameter changes do or do not matter. These results are important for knowledge engineers as they help them identify influential network parameters. They also help explain some of the previous experimental results and observations with regards to network robustness against parameter changes.

Model-Based Diagnosis using Structured System Descriptions

This paper presents a comprehensive approach for model-based diagnosis which includes proposals for characterizing and computing preferred diagnoses, assuming that the system description is augmented with a system structure (a directed graph explicating the interconnections between system components). Specifically, we first introduce the notion of a consequence, which is a syntactically unconstrained propositional sentence that characterizes all consistency-based diagnoses and show that standard characterizations of diagnoses, such as minimal conflicts, correspond to syntactic variations on a consequence. Second, we propose a new syntactic variation on the consequence known as negation normal form (NNF) and discuss its merits compared to standard variations. Third, we introduce a basic algorithm for computing consequences in NNF given a structured system description. We show that if the system structure does not contain cycles, then there is always a linear-size consequence in NNF which can be computed in linear time. For arbitrary system structures, we show a precise connection between the complexity of computing consequences and the topology of the underlying system structure. Finally, we present an algorithm that enumerates the preferred diagnoses characterized by a consequence. The algorithm is shown to take linear time in the size of the consequence if the preference criterion satisfies some general conditions.

Query DAGs: A Practical Paradigm for Implementing Belief-Network Inference

We describe a new paradigm for implementing inference in belief networks, which consists of two steps: (1) compiling a belief network into an arithmetic expression called a Query DAG (Q-DAG); and (2) answering queries using a simple evaluation algorithm. Each node of a Q-DAG represents a numeric operation, a number, or a symbol for evidence. Each leaf node of a Q-DAG represents the answer to a network query, that is, the probability of some event of interest. It appears that Q-DAGs can be generated using any of the standard algorithms for exact inference in belief networks (we show how they can be generated using clustering and conditioning algorithms). The time and space complexity of a Q-DAG generation algorithm is no worse than the time complexity of the inference algorithm on which it is based. The complexity of a Q-DAG evaluation algorithm is linear in the size of the Q-DAG, and such inference amounts to a standard evaluation of the arithmetic expression it represents. The intended value of Q-DAGs is in reducing the software and hardware resources required to utilize belief networks in on-line, real-world applications. The proposed framework also facilitates the development of on-line inference on different software and hardware platforms due to the simplicity of the Q-DAG evaluation algorithm. Interestingly enough, Q-DAGs were found to serve other purposes: simple techniques for reducing Q-DAGs tend to subsume relatively complex optimization techniques for belief-network inference, such as network-pruning and computation-caching.

[Amiodarone and fetal supraventricular tachycardia. Apropos of a case with neonatal hypothyroidism]

BACKGROUND

Fetal tachycardia can be a cause of in utero death. Its detection is not always easy and its treatment is still controversial.

CASE REPORT

Paroxysms of supraventricular tachycardia were detected on echocardiography at the 25th week of a second pregnancy. The mother was given sotalol, but the supraventricular tachycardia became permanent. At the 27th week of gestation, sotalol was stopped and the mother was given digoxin and the foetus received 2 injections of digoxin, 10 micrograms/kg, via the umbilical cord. As this treatment was only partially effective, the mother was also given amiodarone 800 mg/day at week 28, then the dose was reduced to 400 mg/day. However, at the 31st week, the mother showed signs of digoxin intolerance, and it was replaced by sotalol. Fetal blood tests at week 34 showed a high placental transfer of digoxin and sotalol and a low fetal level of amiodarone. The newborn, a girl, was born at the 36th week having a sinus rhythm. She developed signs of hypothyroidism (T4: 4 micrograms/ml; TSH:325 microliters U/ml at 5 days of life).

CONCLUSION

The placental transfers of sotalol, digoxin and amiodarone are in the range of values known to be effective. The amiodarone responsible for hypothyroidism was given to the mother because she was intolerant to digoxin. Its use must be limited to arrhythmias that are resistant to other drugs or complicated by hydrops fetalis. When used, amiodarone should not be given for more than 6 weeks, and at the lowest possible dose.

[Medical treatment of severe uveitis]

135 patients with chronic uveitis were observed and 23 had therapeutic problems by their severity. The corticoid treatment method, always used in a first time, is studied. When there is corticoresistance, corticodependance or absolute contra-indications, the immunosuppressive drugs are used with reduced doses to avoid an AIDS. The corticoid bolus, the plasma exchange and colchicine are adjuvant treatments. Cyclosporin A brings large hopes but its use is now limited by necessity and serious side effects. Serious uveitis does not answer to a unique therapeutic protocol. The treatment must be adaptable and surgery decided in time.