Continuous and bilevel positive airway pressure may improve radiotherapy delivery in patients with intra-thoracic tumors.

Background: Minimizing tumor motion in radiotherapy for intra-thoracic tumors reduces side-effects by limiting radiation exposure to healthy tissue. Continuous or Bilevel Positive Airway Pressure (CPAP/BiPAP) could achieve this, since it could increase lung inflation and decrease tidal volume variability. We aim to identify the better CPAP/BiPAP setting for minimizing tumor motion. Methods: In 10 patients (5 with lung cancer, 5 with other intra-thoracic tumors), CPAP/BiPAP was tested with the following settings for 10 min each: CPAP 5, 10 and 15 cmH2O and BiPAP 14/10 cmH2O with a lower (7 breaths/min) and higher back-up respiratory rate (BURR initially 1 breath/min above the spontaneous breathing frequency, with the option to adjust if the patient continued to initiate breaths). Electrical impedance tomography was used to analyse end-expiratory lung impedance (EELI) as an estimate of end-expiratory lung volume and tidal impedance variation (TIV) as an estimate of tidal volume. Results: Nine out of ten patients tolerated all settings; one patient could not sustain CPAP-15. A significant difference in EELI was observed between settings (χ2 22.960, p < 0.001), with most increase during CPAP-15 (median (IQR) 1.03 (1.00 - 1.06), normalized to the EELI during spontaneous breathing). No significant differences in TIV and breathing variability were found between settings. Conclusions: This study shows that the application of different settings of CPAP/BiPAP in patients with intra-thoracic tumors is feasible and tolerable. BiPAP with a higher BURR may offer the greatest potential for mitigating tumor motion among the applied settings, although further research investigating tumor motion should be conducted.

Analysis and applications of respiratory surface EMG: report of a round table meeting.

Surface electromyography (sEMG) can be used to measure the electrical activity of the respiratory muscles. The possible applications of sEMG span from patients suffering from acute respiratory failure to patients receiving chronic home mechanical ventilation, to evaluate muscle function, titrate ventilatory support and guide treatment. However, sEMG is mainly used as a monitoring tool for research and its use in clinical practice is still limited-in part due to a lack of standardization and transparent reporting. During this round table meeting, recommendations on data acquisition, processing, interpretation, and potential clinical applications of respiratory sEMG were discussed. This paper informs the clinical researcher interested in respiratory muscle monitoring about the current state of the art on sEMG, knowledge gaps and potential future applications for patients with respiratory failure.

[Interdigital pilonidal sinus of the foot: a peculiar place for a common lesion]. / Interdigitale sinus pilonidalis van de voet.

BACKGROUND: Besides the natal cleft, a pilonidal sinus can also occur in other areas of the body. An uncommon place is the interdigital web space of the toes. A sinus can arise due to penetration of the skin by a hair. The only curative treatment is surgical excision. CASE DESCRIPTION: A 55-year-old man was referred by the GP with an inflammation between his toes. On physical examination we saw a skin defect with hairs and granulation tissue between the fourth and fifth toes of the right foot. It was decided to surgically excise the affected area. Histopathological examination showed a chronical, fibrosing inflammation surrounding a free hair structure, consistent with a pilonidal sinus. The lesion was probably caused by dog hairs, in combination with poor personal hygiene. CONCLUSION: This patient had a pilonidal sinus at an uncommon site. In the event of poorly-understood inflammation between the toes, a pilonidal sinus should be considered.

Pseudoaneurysm of the superior lateral genicular artery following anterior cruciate ligament repair.

BACKGROUND: Pseudoaneurysm is a rare complication of surgery of the knee. The pathogenesis of false aneurysm involves partial arterial laceration, which allows hemorrhage into surrounding soft tissues that confine it. Although most cases in literature described pseudoaneurysms after total knee arthroplasty, it can be associated with arthroscopic knee surgery too. METHODS: Here, we report an uncommon case of a false aneurysm of the superior lateral genicular artery following anterior cruciate ligament ligamentoplasty using an autograft semitendinosus-tendon. RESULTS: Three weeks after anterior cruciate ligament repair, a 25-year old man presented with a painful swelling on his right knee. Computed tomography angiography demonstrated a false aneurysm of the superior lateral genicular artery. Ultrasound-guided percutaneous thrombin injection was performed to exclude the pseudoaneurysm, and the patient recovered well. CONCLUSION: Pseudoaneurysm is an uncommon complication of surgery or trauma of the knee. Although most cases in literature described pseudoaneurysms after total knee arthroplasty, it can be associated with arthroscopic knee surgery too. Ultrasound-guided thrombin injection can be a valuable treatment option.

Effect of Water Addition during Preparation on the Early-Time Photodynamics of CH3 NH3 PbI3 Perovskite Layers.

The effect of water addition during preparation of a CH3 NH3 PbI3 layer on the photodynamics is studied by femtosecond transient absorption. Both the regular perovskite and the aqueous analogue show charge thermalisation on a timescale of about 500 fs. This process is, however, less pronounced in the latter layer. The spectral feature associated with hot charges does not fully decay on this timescale, but also shows a long-lived (sub-ns) component. As water molecules may interfere with the hydrogen bonding between the CH3 NH3+ cations and the inorganic cage, this effect is possibly caused by immobilisation of cation motion, suggesting a key role of CH3 NH3+ dipole reorientation in charge thermalisation. This effect shows the possibility of controlling hot charge carrier cooling to overcome the Shockley-Queisser limit.

Porous Layered Double Hydroxides Synthesized using Oxygen Generated by Decomposition of Hydrogen Peroxide.

Porous magnesium-aluminium layered double hydroxides (LDH) were prepared through intercalation and decomposition of hydrogen peroxide (H2O2). This process generates oxygen gas nano-bubbles that pierce holes in the layered structure of the material by local pressure build-up. The decomposition of the peroxide can be triggered by microwave radiation or chemically by reaction with iodide (I-) ions. The carbonate LDH version [Mg0.80Al0.20(OH)2](CO3)0.1∙mH2O was synthesized by microwave-assisted urea coprecipitation and further modified by iodide or H2O2 intercalation. High resolution Scanning Electron Microscopy (HR-SEM) and Brunauer-Emmet-Teller (BET) analysis were used to assess the morphology and surface area of the new porous materials. The presence of H2O2 in the interlayer region and later decomposition triggered by microwave radiation generated more pores on the surface of the LDH platelets, increasing their specific surface area from initially 9 m2/g to a maximum of 67 m2/g. X-Ray Diffraction showed that the formation of the pores did not affect the remaining crystal structure, allowing possible further functionalization of the material.

Surface micropatterning with zirconia and calcium phosphate ceramics by micromoulding in capillaries.

An increasing demand exists for biomaterials that are able to actively participate in the process of repair and regeneration of damaged or diseased organs and tissues. Patterning of surfaces of biomaterials with distinct chemical or physical cues is an attractive way to obtain spatial control over their interactions with the biological system. In the current study, micromoulding in capillaries method was used to pattern silicon substrates with bioinert yttria-stabilised zirconia or with bioactive calcium phosphate ceramics, both widely used biomaterials in orthopaedics and dentistry. Micrometer-scale patterns consisted of parallel lines with varying width and spacing. Both ceramics were successfully deposited on the substrate in a pattern defined by the mould. While the yttria-stabilised zirconia pattern was highly homogenous and smooth (Rq = 5.5 nm), the calcium phosphate pattern, consisting of dicalcium phosphate anhydrous before, and of ß-tricalcium phosphate after annealing, exhibited a less homogenous morphology and higher roughness (Rq = 893 nm). Both materials allowed attachment and proliferation of the MG-63 osteosarcoma cell line, independent of the pattern used. While a preferential orientation of cells in the direction of the pattern lines was observed for all patterns, this effect was more pronounced on the lines with a width of up to 20 µm on both yttria-stabilised zirconia and calcium phosphate ceramics, as compared to wider patterns. Furthermore, the cells retained an elongated morphology for a longer period of time on narrow patterns. Micromoulding in capillaries appeared to be a suitable method to pattern both types of ceramics, however further optimisation is needed to improve homogeneity and obtain better control over the chemical phase and crystalline structure of calcium phosphate patterns.

One year health status benefits following treatment for new onset or exacerbation of peripheral arterial disease symptoms: the importance of patients' baseline health status.

OBJECTIVE/BACKGROUND: Limited information is available on expected health status gains following invasive treatment in peripheral arterial disease (PAD). One year health status outcomes following invasive treatment for PAD were compared, and whether pre-procedural health status was indicative of 1 year health status gains was evaluated. METHODS: Pre-procedural and 1 year health status (Short Form-12, Physical Component Score [PCS]) was prospectively assessed in a cohort of 474 patients, enrolled from 2 Dutch vascular clinics (March 2006-August 2011), with new or exacerbation of PAD symptoms. One year treatment strategy (invasive vs. non-invasive) and clinical information was abstracted. Quartiles of baseline health status scores and mean 1 year health status change scores were compared by invasive treatment for PAD. The numbers needed to treat (NNT) to obtain clinically relevant changes in 1 year health status were calculated. A propensity weight adjusted linear regression analysis was constructed to predict 1 year PCS scores. RESULTS: Invasive treatment was performed in 39% of patients. Patients with baseline health status scores in the lowest quartile undergoing invasive treatment had the greatest improvement (mean invasive 11.3 ± 10.3 vs. mean non-invasive 5.3 ± 8.5 [p = .001, NNT = 3]), whereas those in the highest quartile improved less (.8 ± 6.3 vs. -3.0 ± 8.2 [p = .025, NNT = 90]). Undergoing invasive treatment (p < .0001) and lower baseline health status scores (p < .0001) were independently associated with greater 1 year health status gains. CONCLUSION: Substantial improvements were found in patients presenting with lower pre-procedural health status scores, whereas patients with higher starting health status levels had less to gain by an invasive strategy.

A new water absorbable mechanical Epidermal skin equivalent: the combination of hydrophobic PDMS and hydrophilic PVA hydrogel.

Research on human skin interactions with healthcare and lifestyle products is a topic continuously attracting scientific studies over the past years. It is possible to evaluate skin mechanical properties based on human or animal experimentation, yet in addition to possible ethical issues, these samples are hard to obtain, expensive and give rise to highly variable results. Therefore, the design of a skin equivalent is essential. This paper describes the design and characterization of a new Epidermal Skin Equivalent (ESE). The material resembles the properties of epidermis and is a first approach to mimic the mechanical properties of the human skin structure, variable with the length scale. The ESE is based on a mixture of Polydimethyl Siloxane (PDMS) and Polyvinyl Alcohol (PVA) hydrogel cross-linked with Glutaraldehyde (GA). It was chemically characterized by XPS and FTIR measurements and its cross section was observed by macroscopy and cryoSEM. Confocal Microscope analysis on the surface of the ESE showed an arithmetic roughness (Ra) between 14-16 µm and contact angle (CA) values between 50-60°, both of which are close to the values of in vivo human skins reported in the literature. The Equilibrium Water Content (ECW) was around 33.8% and Thermo Gravimetric Analysis (TGA) confirmed the composition of the ESE samples. Moreover, the mechanical performance was determined by indentation tests and Dynamo Thermo Mechanical Analysis (DTMA) shear measurements. The indentation results were in good agreement with that of the target epidermis reported in the literature with an elastic modulus between 0.1-1.5 MPa and it showed dependency on the water content. According to the DTMA measurements, the ESE exhibits a viscoelastic behavior, with a shear modulus between 1-2.5MPa variable with temperature, frequency and the hydration of the samples.

Selecting patients during the "learning curve" of endoscopic Totally Extraperitoneal (TEP) hernia repair.

BACKGROUND: Totally Extraperitoneal (TEP) hernia surgery is associated with little postoperative pain and a fast recovery, but is a technically demanding operative procedure. Apart from the surgeon's expertise, patient characteristics and hernia-related variations may also affect the operative time and outcome. METHODS: Patient-related factors predictive of perioperative complications, conversion to open anterior repair, and operative time were studied in a cohort of consecutive patients undergoing TEP hernia repair from 2005 to 2009. RESULTS: A total of 3,432 patients underwent TEP. The mean operative time was 26 min (SD ± 10.9), TEP was converted into an open anterior approach in 26 patients (0.8 %), and perioperative complications were observed in 55 (1.6 %) patients. Multivariable regression analysis showed that a history of abdominal surgery (OR 1.76, 95 per cent confidence interval 1.01-3.06; p = 0.05), and the presence of a scrotal (OR 5.31, 1.20-23.43; p = 0.03) or bilateral hernia (OR 2.25, 1.25-4.06; p = 0.01) were independent predictive factors of perioperative complications. Female gender (OR 5.30. 1.52-18.45; p = 0.01), a history of abdominal surgery (OR 3.96, 1.72- 9.12; p = 0.001), and the presence of a scrotal hernia (OR 34.84, 10.42-116.51, p < 0.001) were predictive factors for conversion. A BMI ≥ 25 (effect size (ES) 1.78, 95 % confidence interval 1.09-2.47; p < 0.001) and the presence of a scrotal (ES 5.81, 1.93-9.68; p = 0.003), indirect (ES 2.78, 2.05- 3.50, p < 0.001) or bilateral hernia (ES 10.19, 9.20-11.08; p < 0.001) were associated with a longer operative time. CONCLUSION: Certain patient characteristics are, even in experienced TEP surgeons, associated with an increased risk of conversion and complications and a longer operative time. For the surgeon gaining experience with TEP, it seems advisable to select relatively young and slender male patients with a unilateral (non-scrotal) hernia and no previous abdominal surgery to enhance patient safety and 'surgeon comfort'.

Dielectrophoretic alignment of metal and metal oxide nanowires and nanotubes: a universal set of parameters for bridging prepatterned microelectrodes.

Nanowires and nanotubes were synthesized from metals and metal oxides using templated cathodic electrodeposition. With templated electrodeposition, small structures are electrodeposited using a template that is the inverse of the final desired shape. Dielectrophoresis was used for the alignment of the as-formed nanowires and nanotubes between prepatterned electrodes. For reproducible nanowire alignment, a universal set of dielectrophoresis parameters to align any arbitrary nanowire material was determined. The parameters include peak-to-peak potential and frequency, thickness of the silicon oxide layer, grounding of the silicon substrate, and nature of the solvent medium used. It involves applying a field with a frequency >10(5) Hz, an insulating silicon oxide layer with a thickness of 2.5 µm or more, grounding of the underlying silicon substrate, and the use of a solvent medium with a low dielectric constant. In our experiments, we obtained good results by using a peak-to-peak potential of 2.1 V at a frequency of 1.2 × 10(5) Hz. Furthermore, an indirect alignment technique is proposed that prevents short circuiting of nanowires after contacting both electrodes. After alignment, a considerably lower resistivity was found for ZnO nanowires made by templated electrodeposition (2.2-3.4 × 10(-3) Ωm) compared to ZnO nanorods synthesized by electrodeposition (10 Ωm) or molecular beam epitaxy (MBE) (500 Ωm).

Feasibility of right-sided total extraperitoneal procedure for inguinal hernia repair after appendectomy: a prospective cohort study.

BACKGROUND: Totally extraperitoneal (TEP) endoscopic hernia surgery is increasingly popular since it is associated with little postoperative pain and with early return to work. Previous appendectomy may preclude preperitoneal dissection in patients with right-sided hernias. The feasibility of TEP surgery in these patients was the subject of the present study. METHODS: Between January 2005 and February 2007 all consecutive patients undergoing TEP surgery were included in a prospective cohort study. The study group consisted of patients with right-sided and bilateral hernias. Operative times, conversions, complication rates, and return to daily activities were recorded. Patients were divided into two groups according to previous appendectomy. RESULTS: A total of 462 patients with right-sided hernias underwent TEP surgery: 421 patients without previous abdominal surgery (group 1) and 41 patients with previous appendectomy (group 2). The conversion rate was significantly higher in group 2: four patients (10%) were converted to open Lichtenstein repair versus five (1%) in group 1 (p = 0.005). However, we found no significant differences in complication rate, operative time, and return to daily activities. CONCLUSIONS: A right-sided (or bilateral) TEP procedure may be performed safely in patients after previous appendectomy. Despite a higher conversion rate, the vast majority of patients can be operated endoscopically.

The effect of adjuvant steroid treatment on serial cerebrospinal fluid changes in tuberculous meningitis.

Three recent studies found that corticosteroids improve clinical outcome and mortality in tuberculous meningitis (TBM), although the exact mechanism of action of the drug remains speculative. A number of reports on the effect of corticosteroids on cerebrospinal fluid (CSF) findings in TBM have been published, often with conflicting results regarding serial cell counts and protein levels. As part of a controlled, randomized trial on the effect of oral prednisone on outcome in childhood TBM at our institution, CSF was collected and analysed weekly during the 1st month of treatment. We found no significant difference in serial CSF cell counts between the steroid and non-steroid groups in the study. However, the steroid group had significantly lower CSF protein and globulin levels after the 1st month of treatment, and a more steady rise in CSF glucose levels than the non-steroid group. Knowledge of the different CSF responses during the course of anti-tuberculosis therapy is important in clinical decision-making.