Post-operative complications of tibial plateau fractures treated with screws or hybrid external fixation.

PURPOSE: To assess the complications and second surgeries rates at 1 year follow-up in a group of patients underwent minimally invasive fixation with screws or hybrid external fixation (HEF) for tibial plateau fractures (TPF). The hypothesis was that low Schatzker (I-IV) TPF would have shown a lower complication rate with respect to high Schatzker (V-VI) TPF. METHODS: 148 patients who underwent minimally invasive surgery with screws or HEF for TPF were included and pooled in two groups: mono-condylar (Schatzker I-IV) and bi-condylar (Schatzker V-VI). The rate of second surgeries and complications, such as stiffness, infection, wound dehiscence and malunion occurred within 1 year, were reported. RESULTS: Statistically significant difference between mono-condylar and bi-condylar groups was found in terms of stiffness (18% vs. 37%, p = 0.01), malunion (4% vs 21%, p = 0.004) and second surgeries (32% vs. 48%, p = 0.049). Associated procedures performed during TPF fixation increased risk of second surgeries (OR 2.1, p < 0.001). No differences in terms of second surgeries and complications were found in bi-condylar group treated with screws and HEF. CONCLUSION: Bi-condylar TPF treated with minimally invasive surgery developed a significantly higher rates of stiffness, malunion and second surgeries within 1 year compared to mono-condylar fractures. Moreover, when an associated procedure was performed, the risk of a reoperation was nearly doubled. Trial registration number PG 0012506 CE AVEC 620/2018/Oss/IOR.

High-responsivity graphene photodetectors integrated on silicon microring resonators.

Graphene integrated photonics provides several advantages over conventional Si photonics. Single layer graphene (SLG) enables fast, broadband, and energy-efficient electro-optic modulators, optical switches and photodetectors (GPDs), and is compatible with any optical waveguide. The last major barrier to SLG-based optical receivers lies in the current GPDs' low responsivity when compared to conventional PDs. Here we overcome this by integrating a photo-thermoelectric GPD with a Si microring resonator. Under critical coupling, we achieve >90% light absorption in a ~6 µm SLG channel along a Si waveguide. Cavity-enhanced light-matter interactions cause carriers in SLG to reach ~400 K for an input power ~0.6 mW, resulting in a voltage responsivity ~90 V/W, with a receiver sensitivity enabling our GPDs to operate at a 10-9 bit-error rate, on par with mature semiconductor technology, but with a natural generation of a voltage, rather than a current, thus removing the need for transimpedance amplification, with a reduction of energy-per-bit, cost, and foot-print.

Photo thermal effect graphene detector featuring 105 Gbit s-1 NRZ and 120 Gbit s-1 PAM4 direct detection.

One of the main challenges of next generation optical communication is to increase the available bandwidth while reducing the size, cost and power consumption of photonic integrated circuits. Graphene has been recently proposed to be integrated with silicon photonics to meet these goals because of its high mobility, fast carrier dynamics and ultra-broadband optical properties. We focus on graphene photodetectors for high speed datacom and telecom applications based on the photo-thermo-electric effect, allowing for direct optical power to voltage conversion, zero dark current, and ultra-fast operation. We report on a chemical vapour deposition graphene photodetector based on the photo-thermoelectric effect, integrated on a silicon waveguide, providing frequency response >65 GHz and optimized to be interfaced to a 50 Ω voltage amplifier for direct voltage amplification. We demonstrate a system test leading to direct detection of 105 Gbit s-1 non-return to zero and 120 Gbit s-1 4-level pulse amplitude modulation optical signals.

Vestibular failure managed with osteopathic manipulative treatment: A report of two cases.

INTRODUCTION: Vestibular failure or hypofunction can be generated by pathologies such as vestibular neuritis (VN), causing the onset of rotatory vertigo and the vestibulo-ocular reflex (VOR) hyporeaction. VN is a post-viral inflammation-producing vestibular nerve-axon impairment, which reaches compensation in 70% of cases. Here, we present two cases of vestibular failure that did not respond to pharmacological therapy, but did show modulated vestibular response after an osteopathic manipulative treatment. Dizziness handicap inventory (DHI) was used to assess disability, while VOR was examined by means of video head impulse test (v-HIT). Case 1 showed bilateral VOR areflexia with severe related disability due to chronic vertigo, while case 2 showed sub-acute VN complicated by intense vomiting. After treatment, both cases had a complete remission of symptoms, with a reduction in DHI score of 60 and 70 points respectively, as well as a normalization of the v-HIT exam. CONCLUSION: OMT might work to modulate VOR, through osteopathic manipulation of the fascial-system and interaction with proprioceptive inputs. Further clinical trials should be performed to investigate the OMT clinical efficacy in uncompensated vestibular neuritis.

Chirp management in silicon-graphene electro absorption modulators.

We study the frequency chirp properties of graphene-on-silicon electro-absorption modulators (EAMs). By experimentally measuring the chirp of a 100 µm long single layer graphene EAM, we show that the optoelectronic properties of graphene induce a large positive linear chirp on the optical signal generated by the modulator, giving rise to a maximum shift of the instantaneous frequency up to 1.8 GHz. We exploit this peculiar feature for chromatic-dispersion compensation in fiber optic transmission thanks to the pulse temporal lensing effect. In particular, we show dispersion compensation in a 10Gb/s transmission experiment on standard single mode fiber with temporal focusing distance (0-dB optical-signal-to-noise ratio penalty) of 60 km, and also demonstrate 100 km transmission with a bit error rate largely lower than the conventional Reed-Solomon forward error correction threshold of 10-3.

Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction? a meta-analysis of 32 studies.

AIMS: Our aim was to perform a meta-analysis of the outcomes of revision anterior cruciate ligament (ACL) reconstruction, comparing the use of different types of graft. MATERIALS AND METHODS: A search was performed of Medline and Pubmed using the terms "Anterior Cruciate Ligament" and "ACL" combined with "revision", "re-operation" and "failure". Only studies that reported the outcome at a minimum follow-up of two years were included. Two authors reviewed the papers, and outcomes were subdivided into autograft and allograft. Autograft was subdivided into hamstring (HS) and bone-patellar tendon-bone (BPTB). Subjective and objective outcome measures were analysed and odds ratios with confidence intervals were calculated. RESULTS: A total of 32 studies met the inclusion criteria. Five studies used HS autografts, eight reported using BPTB autografts, two used quadriceps tendon autografts and eight used various types. Seven studies reported using allografts, while the two remaining used both BPTB autografts and allografts. Overall, 1192 patients with a mean age of 28.7 years (22.5 to 39) and a mean follow-up of 5.4 years (2.0 to 9.6) were treated with autografts, while 269 patients with a mean age of 28.4 years (25 to 34.6) and a mean follow-up of 4.0 years (2.3 to 6.0) were treated with allografts. Regarding allografts, irradiation with 2.5 mrad was used in two studies while the graft was not irradiated in the seven remaining studies. Reconstructions following the use of autografts had better outcomes than those using allograft with respect to laxity, measured by KT-1000/2000 (MEDmetric Corporation) and the rates of complications and re-operations. Those following the use of allografts had better mean Lysholm and Tegner activity scores compared with autografts. If irradiated allografts were excluded from the analysis, outcomes no longer differed between the use of autografts and allografts. Comparing the types of autograft, all outcomes were similar except for HS grafts which had better International Knee Documentation Committee scores compared with BPTB grafts. CONCLUSION: Autografts had better outcomes than allografts in revision ACL reconstruction, with lower post-operative laxity and rates of complications and re-operations. However, after excluding irradiated allografts, outcomes were similar between autografts and allografts. Overall, the choice of graft at revision ACL reconstruction should be on an individual basis considering, for instance, the preferred technique of the surgeon, whether a combined reconstruction is required, the type of graft that was previously used, whether the tunnels are enlarged and the availability of allograft. Cite this article: Bone Joint J 2017;99-B:714-23.

Is there a role for femoral offset restoration during total hip arthroplasty? A systematic review.

Benefits of femoral offset restoration during total hip arthroplasty should be the reduction of bearing surfaces wear, implant loosening and dislocation rates. Modular neck stems ensure offset customization but fretting corrosion and catastrophic failures are well-documented complications. Since clinical evidences are needed to substantiate the effectiveness of femoral offset restoration and promote modular neck choice, we systematically reviewed the literature to ascertain whether femoral offset itself has a proven clinical influence: (1) on bearing surfaces wear, (2) implant loosening, (3) and dislocation rates. A systematic literature screening was conducted to find papers dealing with the influence of femoral offset on wear, dislocation and loosening, including articles with conventional radiographic femoral offset assessment and with comparative design. Observational studies, case reports, instructional course lectures, cadaveric and animal studies as well as biomechanical studies, letters to the editor, surgical techniques or technical notes were all excluded. No limits about publication date were supplied but only papers in English were taken into account. Data were extracted into an anonymous spreadsheet. Offset values, dislocation rates, wear rates, follow-up and surgical approaches were all detailed. Ten manuscripts were finally selected. A statistically significant correlation between femoral offset restoration and the reduction of conventional ultrahigh-molecular-weight polyethylene wear was found in two out of three papers investigating this issue, but no correlations were found between femoral offset and dislocation rates or implant loosening. Femoral offset modification influences ultrahigh-molecular-weight polyethylene liners wear, but no correlation was found with dislocation rates or implant loosening. Advantages on wear can be counterbalanced by the use of hard bearing surfaces or highly cross-linked polyethylene liners, besides the availability of larger femoral heads improving implant stability further reduces the importance of femoral offset restoration by means of modularity. We believe that efforts in restoring femoral offset during total hip arthroplasty do not translate into tangible clinical profits and consequently, we do not advise the routinely usage of modular neck stems in total hip arthroplasty. LEVEL OF EVIDENCE: level III, systematic review of case-control studies.

p53 deficiency induces cancer stem cell pool expansion in a mouse model of triple-negative breast tumors.

Triple-negative breast cancer is a heterogeneous disease characterized by the expression of basal cell markers, no estrogen or progesterone receptor expression and a lack of HER2 overexpression. Triple-negative tumors often display activated Wnt/ß-catenin signaling and most have impaired p53 function. We studied the interplay between p53 loss and Wnt/ß-catenin signaling in stem cell function and tumorigenesis, by deleting p53 from the mammary epithelium of K5ΔNßcat mice displaying a constitutive activation of Wnt/ß-catenin signaling in basal cells. K5ΔNßcat transgenic mice present amplification of the basal stem cell pool and develop triple-negative mammary carcinomas. The loss of p53 in K5ΔNßcat mice led to an early expansion of mammary stem/progenitor cells and accelerated the formation of triple-negative tumors. In particular, p53-deficient tumors expressed high levels of integrins and extracellular matrix components and were enriched in cancer stem cells. They also overexpressed the tyrosine kinase receptor Met, a feature characteristic of human triple-negative breast tumors. The inhibition of Met kinase activity impaired tumorsphere formation, demonstrating the requirement of Met signaling for cancer stem cell growth in this model. Human basal-like breast cancers with predicted mutated p53 status had higher levels of MET expression than tumors with wild-type p53. These results connect p53 loss and ß-catenin activation to stem cell regulation and tumorigenesis in triple-negative cancer and highlight the role of Met signaling in maintaining cancer stem cell properties, revealing new cues for targeted therapies.

Wide-band polarization controller for Si photonic integrated circuits.

A circuit for the management of any arbitrary polarization state of light is demonstrated on an integrated silicon (Si) photonics platform. This circuit allows us to adapt any polarization into the standard fundamental TE mode of a Si waveguide and, conversely, to control the polarization and set it to any arbitrary polarization state. In addition, the integrated thermal tuning allows kilohertz speed which can be used to perform a polarization scrambler. The circuit was used in a WDM link and successfully used to adapt four channels into a standard Si photonic integrated circuit.

Complex effective index in graphene-silicon waveguides.

We report for the first time and characterize experimentally the complex optical conductivity of graphene on silicon photonic waveguides. This permits us to predict accurately the behavior of photonic integrated devices encompassing graphene layers. Exploiting a Si microring add/drop resonator, we show the effect of electrical gating of graphene on the complex effective index of the waveguide by measuring both the wavelength shift of the resonance and the change in the drop peak transmission. Due to electro-refractive effect of graphene a giant (>10-3) change in the effective index is demonstrated for the first time on Si photonics waveguides and this large effect will crucially impact performances and consumption of Si photonics devices. We confirmed the results by two independent experiments involving two different gating schemes: Si gating through the ridge waveguide, and polymer-electrolyte gating. Both the experiments demonstrate a very large phase effect in good agreement with numerical calculations. The reported results validate the Kubo model for the case of graphene-Si photonics interfaces and for propagation in this type of waveguide. This is fundamental for the next design and fabrication of future graphene-silicon photonics devices.

High responsivity SiGe heterojunction phototransistor on silicon photonics platform.

We report on a novel near infrared SiGe phototransistor fabricated by a standard silicon photonics foundry. The device is first investigated by simulations. The fabricated devices are characterized in terms of current-voltage characteristics at different optical power. Typical phototransistors exhibit 1.55µm record responsivity at low optical power exceeding 232A/W and 42A/W at 5V and 1V bias, respectively. A differential detection scheme is also proposed for the dark current cancellation to significantly increase the device sensitivity.

Hemoconcentration induced by exercise: Revisiting the Dill and Costill equation.

The Dill and Costill equation is used to estimate the exercise-induced hemoconcentration. However, this calculation requires drawing an extra whole-blood sample, which cannot be frozen and has to be analyzed with dedicate instrumentation in a relative short time. The aim of the present study was to explore the usefulness of some serum biochemical parameters to estimate hemoconcentration induced by exhaustive exercise. Fourteen healthy male subjects (19-34 years) performed a15-min running test at 110% of anaerobic threshold speed. Hemoglobin, hematocrit, brain natriuretic peptide (BNP), creatinine, gamma-glutamyltransferase (GGT), total-proteins, albumin, total calcium (Ca), K(+), Na(+), and Cl(-) were determined in blood samples taken before, after exercise, and after a 30-min recovery period. Plasma volume loss (ΔPV) was calculated by Dill and Costill equation. At post-exercise and after recovery, the percentage increments of total-proteins, albumin, GGT and Ca correlated significantly with ΔPV. Bland-Altman analyses showed that correcting BNP, creatinine, and K(+) concentration by Ca percentage increments yield biases and limits of agreement that are acceptable when compared with Dill and Costill equation correction. Ca concentration may be used as a hemoconcentration biomarker in high-intensity exercise, which would allow scientists and physicians avoid extra costs, facilitate in-field research, and delayed estimation of hemoconcentration using stored serum samples.

Exercise effects on erythrocyte deformability in exercise-induced arterial hypoxemia.

Exercise-induced arterial hypoxemia (EIAH) is often found in endurance-trained subjects at high exercise intensity. The role of erythrocyte deformability (ED) in EIAH has been scarcely explored. We aimed to explore the role of erythrocyte properties and lactate accumulation in the response of ED in EIAH. ED was determined in 10 sedentary and in 16 trained subjects, both before and after a maximal incremental test, and after recovery, along with mean corpuscular volume (MCV) and red blood cell lactate concentrations. EIAH was found in 6 trained subjects (∆SaO2=-8.25±4.03%). Sedentary and non-EIAH trained subjects showed reduced ED after exercise, while no effect on ED was found in EIAH trained subjects. After exercise, lactate concentrations rose and MCV increased equally in all groups. ED is strongly driven by cell volume, but the different ED response to exercise in EIAH shows that other cellular mechanisms may be implicated. Interactions between membrane and cytoskeleton, which have been found to be O2-regulated, play a role in ED. The drop in SaO2 in EIAH subjects can improve ED response to exercise. This can be an adaptive mechanism that enhances muscular and pulmonary perfusion, and allows the achievement of high exercise intensity in EIAH despite lower O2 arterial transport.

Effects of an acute high-intensity interval training protocol on plasma viscosity.

AIM: High-intensity interval training (HIT) is an exercise model that has been seen to cause similar muscle adaptations and improvements in exercise performance to other traditional exercise models. This study aimed to examine the effects of low-volume HIT exercise on plasma viscosity (PV). METHODS: Ten healthy male subjects (25.80±3.39 years) randomly performed a HIT running protocol (2-min warm up at 8 km/h, 5x2-min bouts at 90% maximal heart rate, separated by 2-min at 8 km/h, finished with another 2-min period at 8 km/h) or an aerobic (AER) running exercise (60'at 55% VO2max). Blood samples were drawn before and after exercise, and after 30-minute recovery. PV, hematocrit (Hct), fibrinogen, total proteins, triglycerides, total-cholesterol and glucose levels were analyzed. Plasma volume loss during exercise was calculated. RESULTS: PV rose after HIT (P<0.05) while Hct rose after both protocols. Plasma volume loss was higher after HIT (-6.35±3.47%) than after AER (-3.11±2.49%) (P=0.045). Total-proteins (P<0.001), triglycerides (P=0.013), total-cholesterol (P<0.001) and glucose (P=0.001) concentrations increased after HIT. After AER no statistically significant differences were found in plasma constituents concentrations. CONCLUSION: A low-volume HIT session causes a sufficient loss in plasma volume that leads to significantly incremented plasma constituents' concentrations and, therefore, a mild transient rise in PV.

Idiopathic pulmonary fibrosis clustering based on cilium gene expression: profiling a new paradigm.

Idiopathic pulmonary fibrosis (IPF), the commonest form of the interstitial lung diseases identifies a specific form of chronic, progressive fibrosing interstitial pneumonia, occurring primarily in older adults, and limited to the lungs. IPF represents an unsolved health problem with an urgent medical need due to lack of effective therapies. Although precise IPF etiology remains elusive, during the past decade there has been a shift away from the pathogenetic theory of generalized inflammation progressing to a paradigm of disordered fibroproliferation and alveolar epithelial cell function. A better understanding of the molecular mechanisms driving IPF fibroblasts proliferation is mandatory to provide insights into the pathogenesis, and to identify highly reproducible biomarkers for disease onset and progression. In this review we aim to discuss and analyze the findings recently published by Yang et al. on Thorax, which reported a strong molecular signature as-sociated with the expression of cilium genes that divides IPF/ usual interstitial pneumonia into two subtypes, one with increased cilium gene expression and one with low expression of cilium genes. The study presents a number of methodology limitations, mainly related to samples characterization and to a general overstatement of the conclusions from class clustering analysis. Nevertheless, the study clearly demonstrates ­ for the first time ­ that the cilium apparatus is activated in microscopic honeycombing. In such setting, cilia are likely to act as signaling "machine" which cooperates in promoting proliferative and regenerative cellular processes. Although preliminary, these results sustain a rationale to develop further investigations to confirm the impact of cilium gene expression in IPF with the final perspective of therapeutic intervention.

Inconsistency in circulating irisin levels: what is really happening?

The discovery of irisin as a novel and promising peptidic hormone for the treatment of obesity and diabetes has recently been reported. As a result, great hopes have been raised based on this finding, hypothesizing that irisin might provide additional benefits, not only for obesity and diabetes, but also for a wide range of pathological conditions requiring therapeutical and clinical attention. However, controversial results and conclusions on circulating irisin concentrations and correlations with other variables, including its role in metabolism, have recently been reported. Although laboratory assessment of irisin by ELISA is easily available and may provide interesting information for therapeutics and clinical practice, the heterogeneous and often discrepant results published so far, raise serious concerns about its measurement, indicating that it may still not be ready for use or whether irisin really exists. We highlight here some aspects on these discrepancies and contradictions, and put forward their implications.

Multicenter evaluation of the Sepsityper™ extraction kit and MALDI-TOF MS for direct identification of positive blood culture isolates using the BD BACTEC™ FX and VersaTREK(®) diagnostic blood culture systems.

AIMS: (i) Evaluation of delayed time to blood culture extraction by the Sepsityper kit and impact of shipping pellets off-site for MALDI-TOF MS analysis. (ii) Comparison of Sepsityper and laboratory-developed extraction methods from a literature review. METHODS AND RESULTS: Using two blood culture systems (BD BACTEC and VersaTREK), we extracted 411 positive blood cultures using the Sepsityper kit to mimic a potential protocol for institutions without a MALDI-TOF MS. Extracted pellets were shipped and analysed on the Bruker UltraflexIII. Successful extraction of 358 (87·1%) samples was determined by the presence of detectable proteins. MALDI-TOF MS correctly identified 332 (80·8%) samples. CONCLUSIONS: Delayed time to extraction did not affect Sepsityper extraction or MALDI-TOF MS accuracy. The extracted pellets remain stable and provide accurate results by MALDI-TOF MS when shipped at room temperature to off-site reference laboratories. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to show that institutions without a MALDI-TOF MS can take advantage of this innovative technology by shipping a volume of blood to an off-site laboratory for extraction and MALDI-TOF MS analysis. We also performed a literature review to compare various extraction methods.

The effect of anticoagulant therapy for idiopathic pulmonary fibrosis in real life practice.

BACKGROUND: IPF is a common form of interstitial lung disease for which there is no effective therapy and usually results in death. Two previous contradictory studies showed anticoagulant therapy  to be associated with both improved and worsened survival, respectively. OBJECTIVE: The objective of this retrospective cohort study was to evaluate the effect of anticoagulant therapy on the survival and disease progression of patients with idiopathic pulmonary fibrosis (IPF) in real clinical practice. METHODS: We compared the clinical characteristics, time to disease progression, incidence of acute exacerbation, and survival of 25 (20%) IPF patients receiving anticoagulant therapy to the remaining 97 IPF patients not receiving anticoagulant therapy. In addition we conducted a sensitivity analysis using as comparator a group of 25 patients matched by age, sex, functional impairment, cardiac comorbidities and pulmonary hypertension. RESULTS: Patients on anticoagulant therapy had a worse 1- and 3-year survival (84% and 53% versus 89% and 64% in the non-anticoagulant group, respectively), a difference that persisted after adjusting for age and comorbidities (hazard ratio 3.1 - 95% confidence interval, 1.4 to 7.0; p=0.006) and after comparison with the matched group (adjusted HR=4.8, 95% CI: 1.8-12.8; p=0.002). IPF patients on anticoagulant therapy had a shorter interval to disease progression ( 0.7 years versus 1.6 years, adjusted HR 2.2 -95% CI, 0.96 to 5.1; p=0.063) confirmed also in the analysis with matched subgroups (HR=2.7 (95% CI: 1.2-6.5); p=0.023). The incidence of acute exacerbations did not differ in the two groups (22% versus 23%). Two patients (8%) experienced anticoagulant treatment related complications and included an episode of hemorrhagic shock. CONCLUSION: In this retrospective study patients treated with anticoagulants had a worse survival and a shorter interval to disease progression. This support the recent finding that warfarin worsen the respiratory status and survival of IPF patients.