Prevention of Cutibacterium acnes infection in arthroscopic shoulder surgery: a systematic review.

BACKGROUND: Cutibacterium acnes is a gram-positive anaerobe that can lead to postoperative shoulder infections. The purpose of this study was to determine the incidence of C acnes infections following shoulder arthroscopy and evaluate the efficacy of perioperative antibiotic prophylaxis in the prevention of these infections. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify studies that evaluated the prevalence and clinical indications of C acnes infections after various arthroscopic shoulder surgical procedures. Patients were assessed based on positive culture rates, the contraction of infection, and antibiotic regimens used to prevent infection. RESULTS: A total of 9 studies (1 level I, 5 level II, 1 level III, and 2 level IV) met the inclusion criteria, including a total of 3758 patients with a mean age of 59.9 years (range, 17-87 years) at the time of surgery. The mean follow-up time was 1.6 months (range, 1.0-12.0 months). Overall, 37.3% of patients (173 of 464) had positive C acnes skin and/or joint culture results, and in 0.22% of patients (8 of 3586), a C acnes infection was diagnosed postoperatively. The application of a topical benzoyl peroxide antibiotic in the days leading up to surgery significantly reduced the positive culture rate from 41.6% to 9.6% (P < .001). CONCLUSIONS: C acnes infections occur at a very low rate (0.22%) following shoulder arthroscopy. The application of a topical benzoyl peroxide antibiotic in the days leading up to surgery in combination with preoperative antibiotic prophylaxis significantly reduces the prevalence of C acnes in shoulder arthroscopy patients.

Comparing Hamstring Autograft With Hybrid Graft for Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To systematically review the literature in an effort to compare the demographics and clinical outcomes of patients undergoing anterior cruciate ligament reconstruction (ACLR) with a hamstring tendon autograft (HT) versus an irradiated or nonirradiated hybrid autograft-allograft. METHODS: A systematic review of the PubMed, Cochrane Library, and Embase databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All English-language literature that reported general demographics and compared the clinical outcomes of patients undergoing primary ACLR with autograft versus hybrid graft (HG) with a minimum 2-year follow-up was reviewed by 2 independent reviewers. Search terms used were "anterior cruciate ligament" and "hybrid graft." Patients were assessed based on graft failure, anteroposterior laxity, and patient-reported outcomes (Knee Injury and Osteoarthritis Outcome Score, visual analog scale, Subjective International Knee Documentation Committee score, Lysholm, and Tegner scores). Study quality was evaluated with the Modified Coleman Methodology Score and ROBINS-I risk of bias tool. RESULTS: Twelve studies (1 level II, 11 level III) met inclusion criteria (follow-up, 2.0-8.9 years), including 471 patients undergoing ACLR with an irradiated hybrid graft (IH), 89 patients with a nonirradiated hybrid graft, and 829 patients with HT. Graft diameter ranged from 7.5 to 10.0 mm and from 6.5 to 10.0 mm in HG and HT patients, respectively. Overall, graft failure ranged from 0% to 30.0% and from 0% to 28.3% in HG and HT patients, respectively (I2 = 35.9%; 95% confidence interval 0%-74.8%). Among HG patients, graft failure ranged from 0%-30.0% and from 2.4%-4.2% in IH and nonirradiated hybrid graft groups, respectively (I2 = 33.6%; 95% confidence interval, 0%-71.8%). Results for postoperative anteroposterior laxity and patient-reported outcomes were also inconsistent. CONCLUSIONS: Patients undergoing ACLR with HT demonstrate inconsistent differences in clinical outcomes at midterm follow-up compared with IH patients. LEVEL OF EVIDENCE: III, systematic review of level II and III studies.

Nonarthroplasty Surgical Treatment Options for Massive, Irreparable Rotator Cuff Tears.

Massive, irreparable rotator cuff tears (MIRCTs) provide a significant dilemma for orthopaedic surgeons. One treatment option for MIRCTs is reverse total shoulder arthroplasty. However, other methods of treating these massive tears have been developed. A search of the current literature on nonoperative management, arthroscopic debridement, partial repair, superior capsular reconstruction (SCR), graft interposition, balloon spacer arthroplasty, trapezius transfer, and latissimus dorsi transfer for MIRCTs was performed. Studies that described each surgical technique and reported on clinical outcomes were included in this review. Arthroscopic debridement may provide pain relief by removing damaged rotator cuff tissue, but no functional repair is performed. Partial repair has been suggested as a technique to restore shoulder functionality by repairing as much of the rotator cuff tendon as possible. This technique has demonstrated improved clinical outcomes but also fails at a significantly high rate. SCR has recently gained interest as a method to prohibit superior humeral head translation and has been met with encouraging early clinical outcomes. Graft interposition bridges the gap between the retracted tendon and humerus. Balloon spacer arthroplasty has also been recently proposed and acts to prohibit humeral head migration by placing a biodegradable saline-filled spacer between the humeral head and acromion; it has been shown to provide good clinical outcomes. Both trapezius and latissimus dorsi transfer techniques involve transferring the tendon of these respective muscles to the greater tuberosity of the humerus; these 2 techniques have shown promising restoration in shoulder function, especially in a younger, active population. Arthroscopic debridement, partial repair, SCR, graft interposition, balloon spacer arthroplasty, trapezius transfer, and latissimus dorsi transfer have all been shown to improve clinical outcomes for patients presenting with MIRCTs. Randomized controlled trials are necessary for confirming the efficacy of these procedures and to determine when each is indicated based on specific patient and anatomic factors.

Multi-scale classification based lesion segmentation for dermoscopic images.

This paper presents a robust segmentation method based on multi-scale classification to identify the lesion boundary in dermoscopic images. Our proposed method leverages a collection of classifiers which are trained at various resolutions to categorize each pixel as "lesion" or "surrounding skin". In detection phase, trained classifiers are applied on new images. The classifier outputs are fused at pixel level to build probability maps which represent lesion saliency maps. In the next step, Otsu thresholding is applied to convert the saliency maps to binary masks, which determine the border of the lesions. We compared our proposed method with existing lesion segmentation methods proposed in the literature using two dermoscopy data sets (International Skin Imaging Collaboration and Pedro Hispano Hospital) which demonstrates the superiority of our method with Dice Coefficient of 0.91 and accuracy of 94%.

Tonsillar Syphilis: an Unusual Site of Infection Detected by Treponema pallidum PCR.

With the reemergence of syphilis, it is important that both clinical and public health practitioners recognize the various clinical manifestations of this disease (formerly known as "the great imitator") and become familiar with the newer diagnostic tests. Here we report the first case of tonsillar syphilis diagnosed by PCR.

Automated medical image modality recognition by fusion of visual and text information.

In this work, we present a framework for medical image modality recognition based on a fusion of both visual and text classification methods. Experiments are performed on the public ImageCLEF 2013 medical image modality dataset, which provides figure images and associated fulltext articles from PubMed as components of the benchmark. The presented visual-based system creates ensemble models across a broad set of visual features using a multi-stage learning approach that best optimizes per-class feature selection while simultaneously utilizing all available data for training. The text subsystem uses a pseudoprobabilistic scoring method based on detection of suggestive patterns, analyzing both the figure captions and mentions of the figures in the main text. Our proposed system yields state-of-the-art performance in all 3 categories of visual-only (82.2%), text-only (69.6%), and fusion tasks (83.5%).

Dynamics of glass relaxation at room temperature.

The problem of glass relaxation under ambient conditions has intrigued scientists and the general public for centuries, most notably in the legend of flowing cathedral glass windows. Here we report quantitative measurement of glass relaxation at room temperature. We find that Corning® Gorilla® Glass shows measurable and reproducible relaxation at room temperature. Remarkably, this relaxation follows a stretched exponential decay rather than simple exponential relaxation, and the value of the stretching exponent (ß=3/7) follows a theoretical prediction made by Phillips for homogeneous glasses.

Resonance Raman and UV-visible spectroscopy of black dyes on textiles.

Resonance Raman and UV-visible diffuse reflectance spectra were recorded from samples of cotton, viscose, polyester, nylon, and acrylic textile swatches dyed black with one of seven single dyes, a mixture of two dyes, or one of seven mixtures of three dyes. The samples generally gave characteristic Raman spectra of the dyes, demonstrating that the technique is applicable for the forensic analysis of dyed black textiles. Survey studies of the widely used dye Reactive Black 5 show that essentially the same Raman spectrum is obtained on bulk sampling from the dye in solution, on viscose, on cotton at different uptakes, and on microscope sampling from the dye in cotton threads and single fibres. The effects of laser irradiation on the Raman bands and emission backgrounds from textile samples with and without dye are also reported.

On the syntheses, NMR spectroscopic and structural characterisations of [CuL(C(2)H(4))].PF(6) and [Cu(2)L(2)(mu-C(4)H(6))].2PF(6): L = (+/-)-N,N'-bis(2,4,6-trimethylbenzylidene)-1,2-diaminocyclohexane.

Copper(i) (+/-)-N,N'-bis(2,4,6-trimethylbenzylidene)-1,2-diaminocyclohexane reacts with either ethene or butadiene to give the corresponding alkene complexes. In each case crystallographic studies show that the alkene coordinates in an eta(2) fashion. In the butadiene complex a dimer is formed where the butadiene bridges two copper complexes. Variable temperature NMR spectroscopy of the ethene adduct demonstrates fluxional behaviour, which is attributed to the rotation of the coordinated ethene relative to the complex, DeltaG(double dagger)(255) = 50 +/- 2 kJ mol(-1).

Reductive reaction mechanisms of the azo dye Orange II in aqueous solution and in cellulose: from radical intermediates to products.

Reductive reaction mechanisms of the azo dye Orange II (Acid Orange 7) in aqueous solution have been studied from radical intermediates through to the final products using a combination of nanosecond time-resolved UV-visible absorption spectroscopy, steady-state photolysis, and HPLC techniques. The dye is reduced by photochemically produced 2-hydroxy-2-propyl radicals at a near-diffusion-controlled rate (k2 = 2.2 x 10(9) dm3 mol(-1) s(-1)) to give the dye radical anion, which then disproportionates (k3 = 2.6 x 10(8) dm3 mol(-1) s(-1)) to re-form the parent dye and a hydrazine. The hydrazine decomposes to 4-aminobenzenesulfonate and a naphthylimine species, which hydrolyses to give 1,2-naphthoquinone; this naphthoquinone and 4-aminobenzenesulfonate react to give a species that reacts further in the presence of air to form an indophenol dye. The reduction of Orange II has also been studied in cellophane, where the rate constant for dye reduction by 2-hydroxy-2-propyl radicals is approximately two orders of magnitude lower than that in aqueous solution.

Remote site photosubstitution in metalloporphyrin-rhenium tricarbonylbipyridine assemblies: photo-reactions of molecules with very short lived excited states.

The synthesis is reported of a series of metalloporphyrins (and the corresponding free-base porphyrin), mono-meso-substituted with a bipyridyl group via an amide link at the 4-position of one phenyl group: [Re(CO)(3)(Pic)Bpy-MTPP][OTf], where M = Mg, Zn, Pd or 2H, Pic = 3-picoline, Bpy = 2,2'-bipyridine, TPP = tetraphenylporphyrin. The photochemical reactions of the assemblies with the sacrificial electron donor triethylamine have been investigated by IR spectroscopy and compared to the behaviour of analogues of the type Bpy-MTPP without rhenium. Selective long-wavelength irradiation of the metalloporphyrin unit in the presence of excess picoline leads to reduction at the rhenium bipyridine centre. In the absence of 3-picoline, the latter is not reduced, but substituted by added halide or by the THF solvent. Mechanistic analysis highlights the differences between the zinc and magnesium chelate on the one hand and the palladium porphyrin on the other. The free-base assembly, [Re(CO)(3)(Pic)Bpy-H(2)TPP][OTf] is unreactive. The zinc and magnesium porphyrin assemblies initially coordinate Et(3)N before undergoing photo-induced inner-sphere electron transfer from the triethylamine to form a charge-shifted excited state of the assembly. In contrast, the palladium-based dyad reacts via outer-sphere reductive quenching of a porphyrin-based excited state. The substitution products are postulated to form by a mechanism involving an electron-transfer chain.

Kinetic studies on the oxidation of aryl methyl sulfides and sulfoxides by dimethyldioxirane; absolute rate constants and activation parameters for 4-nitrophenyl methyl sulfide and sulfoxide.

The oxidations of methyl 4-nitrophenyl sulfide and sulfoxide by dimethyldioxirane, in acetone and mixtures of acetone with water, methanol, acetonitrile and hexane, have been followed by UV-Vis spectroscopy to monitor the decay of the substrates. The data show that, under all the conditions studied, both oxidations obey second-order kinetics. Grunwald-Winstein and Kamlet-Taft analyses of the influence of solvents on the second-order rate constants have been used to obtain mechanistic information on the two reactions. Activation parameters for the two oxidations in acetone and aqueous acetone have been calculated from rate constants for reactions in the temperature range 283-313 K and compared with those from sulfide and sulfoxide oxidations with other oxidants. For sulfoxide oxidations in acetone and 1-20% v/v water in acetone, the results support a concerted nucleophilic displacement by sulfur of oxygen from dimethyldioxirane with the rate being dependent on the solvent's polarity. Sulfide oxidations in acetone and 1-5% v/v water in acetone also proceed by a concerted mechanism. However, in the most polar solvent system studied, 20% v/v water in acetone, the mechanism changes in favour of a two-step reaction involving a betaine intermediate. Importantly, the sulfide oxidation shows a different solvent dependence to that of the sulfoxide, with the rate of oxidation being determined by the hydrogen bond donor capacity and electron-pair donicity of the solvent.

An investigation by means of correlation analysis into the mechanisms of oxidation of aryl methyl sulfides and sulfoxides by dimethyldioxirane in various solvents.

Relative rate constants have been measured for the oxidation of aryl methyl sulfides and sulfoxides by dimethyldioxirane in acetone, in mixtures of acetone with aprotic co-solvents of both higher and lower relative permittivity, and in aqueous acetone mixtures. Correlation analyses of the effects of substituents in the different solvents show that, with one exception, reactions take place via a single step mechanism in which the formation of the new SO bond and the elimination of acetone occur concertedly. The exception was oxidation of the sulfides in aqueous acetone containing the highest proportion of water of those studied (20% v/v). Here, the behaviour of the reaction is consistent with a two-step mechanism in which the oxidant reversibly attacks the sulfide to form an open-chain sulfonium betaine that subsequently fragments to sulfoxide and acetone. There is no evidence for the participation of an intermediate dioxathietane as has been found in the case of sulfide oxidations by (trifluoromethyl)methyldioxirane in CH(2)Cl(2) and similar aprotic solvents. It is not justified to generalise a mechanism involving a betaine, with or without a derived dioxathietane, to the reactions of dimethyldioxirane in acetone.

Ultrafast charge separation in a photoreactive rhenium-appended porphyrin assembly monitored by picosecond transient infrared spectroscopy.

Rhenium(bipyridine)(tricarbonyl)(picoline) units have been linked covalently to tetraphenylmetalloporphyrins of magnesium and zinc via an amide bond between the bipyridine and one phenyl substituent of the porphyrin. The resulting complexes, abbreviated as [Re(CO)(3)(Pic)Bpy-MgTPP][OTf] and [Re(CO)(3)(Pic)Bpy-ZnTPP][OTf], exhibit no signs of electronic interaction between the Re(CO)(3)(bpy) units and the metalloporphyrin units in their ground states. However, emission spectroscopy reveals solvent-dependent quenching of porphyrin emission on irradiation into the long-wavelength absorption bands localized on the porphyrin. The characteristics of the excited states have been probed by picosecond time-resolved absorption (TRVIS) spectroscopy and time-resolved infrared (TRIR) spectroscopy in nitrile solvents. The presence of the charge-separated state involving electron transfer from MgTPP or ZnTPP to Re(bpy) is signaled in the TRIR spectra by a low-frequency shift in the nu(CO) bands of the Re(CO)(3) moiety similar to that observed by spectroelectrochemical reduction. Long-wavelength excitation of [Re(CO)(3)(Pic)Bpy-MTPP][OTf] results in characteristic TRVIS spectra of the S(1) state of the porphyrin that decay with a time constant of 17 ps (M = Mg) or 24 ps (M = Zn). The IR bands of the CS state appear on a time scale of less than 1 ps (Mg) or ca. 5 ps (Zn) and decay giving way to a vibrationally excited (i.e., hot) ground state via back electron transfer. The IR bands of the precursors recover with a time constant of 35 ps (Mg) or 55 ps (Zn). The short lifetimes of the charge-transfer states carry implications for the mechanism of reaction in the presence of triethylamine.

Si/Cu interface structure and adhesion.

An ab initio investigation of the Si(111)/Cu(111) interfacial atomic structure and adhesion is reported. Misfit dislocations appear naturally, as do hcp interfacial silicide phases that vary with temperature. The silicides form in the interface even at relatively low temperatures. These results are consistent with available experimental data.

Ultrasonic estimation of fetal weight at term: an evaluation of eight formulae.

AIM: To compare the accuracy of eight sonographic formulae for predicting fetal birth weight at term in a multiethnic population. METHODS: Pregnant women at term who were booked for induction of labor or elective cesarean section were included in the study. Eight ultrasonic fetal biometric formulae were used to predict fetal birth weight. RESULTS: A total of 173 patients were included in the study; 53 (30.6%) patients were from the Indian subcontinent, 44 (25.4%) patients were from Africa, 33 (19.1%) patients were from the Arabian Peninsula and 43 (24.9%) were from other ethnic groups. The mean absolute error ranged from a minimum of 0.3% (+/-11.3) for Hadlock (biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC], femur length [FL]) to a maximum of 37.5% (+/-10.0) for Warsof (FL). The correlation of estimated fetal weight with actual birth weight ranged from a minimum of 0.09 with Warsof (FL) to a maximum of 0.77 with Shepard and Warsof (BPD, AC) and Hadlock (BPD, HC, AC, FL). The combination of AC with BPD measurements rather than FL achieves a high level of accuracy. CONCLUSIONS: Shepard (BPD, AC) provides a simple and accurate logarithm for the prediction of fetal weight at term in the studied multiethnic population.

Experimental and computational studies of structure and bonding in parent and reduced forms of the azo dye Orange II.

The structure and bonding of the azo dye Orange II (Acid Orange 7) in parent and reduced forms have been studied using NMR, infrared, Raman, UV-visible, and electron paramagnetic resonance (EPR) spectroscopy, allied with density functional theory (DFT) calculations on three hydrazone models (no sulfonate, anionic sulfonate, and protonated sulfonate) and one azo model (protonated sulfonate). The calculated structures of the three hydrazone models are similar to each other and that of the model without a sulfonate group (Solvent Yellow 14) closely matches its reported crystal structure. The 1H and 13C NMR resonances of Orange II, assigned directly from 1D and 2D experimental data, indicate that it is present as > or = 95% hydrazone in aqueous solution, and as a ca. 70:30 hydrazone:azo mixture in dimethyl sulfoxide at 300 K. Overall, the experimental data from Orange II are matched well by calculations on the hydrazone model with a protonated sulfonate group; the IR, Raman, and UV-visible spectra of Orange II are assigned to specific vibrational modes and electronic transitions calculated for this model. The EPR spectrum obtained on one-electron reduction of Orange II by the 2-hydroxy-2-propyl radical (*CMe2OH) at pH 4 is attributed to the hydrazyl radical produced on protonation of the radical anion. Calculations on reduced forms of the model dyes support this assignment, with electron spin density on the two nitrogen atoms and the naphthyl ring; in addition, they provide estimates of the structures, vibrational spectra, and electronic transitions of the radicals.

A manganese superoxide dismutase mimic based on cis,cis-1,3,5-triaminocyclohexane.

A novel manganese(iii) complex with a water soluble cis,cis-1,3,5-triaminocyclohexane-based ligand was synthesised and shown to exhibit superoxide dismutase activity.

Formation and reaction of O=MnV species in the oxidation of phenolic substrates with H2O2 catalysed by the dinuclear manganese(IV) 1,4,7-trimethyl-1,4,7-triazacyclononane complex [MnIV2(mu-O)3(TMTACN)2](PF6)2.

The oxidation of phenolic substrates with H2O2 catalysed by [MnIV2(mu-O)3(TMTACN)2](PF6)2 1, (TMTACN, 1,4,7-trimethyl-1,4,7-triazacyclononane) has been investigated by use of ESI mass spectrometry. The role of the phenols as one-electron reductants and as co-ligands in the stabilisation and reaction of an intermediate O=MnV species has been analysed and the presence of a variety of manganese species in solution has been explained. Our results lead to a proposed mechanism for the catalytic oxidation of phenols in this system.