Isotopic Control of the Boron-Vacancy Spin Defect in Hexagonal Boron Nitride

We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V_{B}^{-}) centers hosted in isotopically engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with ^{15}N yields a simplified and well-resolved hyperfine structure of V_{B}^{-} centers, while purification with ^{10}B leads to narrower ESR linewidths. These results establish isotopically purified h^{10}B^{15}N crystals as the optimal host material for future use of V_{B}^{-} spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically induced polarization of ^{15}N nuclei in h^{10}B^{15}N, whose mechanism relies on electron-nuclear spin mixing in the V_{B}^{-} ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.

Optically Active Spin Defects in Few-Layer Thick Hexagonal Boron Nitride

Optically active spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of two-dimensional quantum sensing units offering optimal proximity to the sample being probed. In this Letter, we first demonstrate that the electron spin resonance frequencies of boron vacancy centers (V_{B}^{-}) can be detected optically in the limit of few-atomic-layer thick hBN flakes despite the nanoscale proximity of the crystal surface that often leads to a degradation of the stability of solid-state spin defects. We then analyze the variations of the electronic spin properties of V_{B}^{-} centers with the hBN thickness with a focus on (i) the zero-field splitting parameters, (ii) the optically induced spin polarization rate and (iii) the longitudinal spin relaxation time. This Letter provides important insights into the properties of V_{B}^{-} centers embedded in ultrathin hBN flakes, which are valuable for future developments of foil-based quantum sensing technologies.

Nanoporous GaN by selective area sublimation through an epitaxial nanomask: AlN versus SixNy

Nanoporous GaN layers were fabricated using selective area sublimation through a self-organized AlN nanomask in a molecular beam epitaxy reactor. The obtained pore morphology, density and size were measured using plan-view and cross-section scanning electron microscopy experiments. It was found that the porosity of the GaN layers could be adjusted from 0.04 to 0.9 by changing the AlN nanomask thickness and sublimation conditions. The room temperature photoluminescence properties as a function of the porosity were analysed. In particular, a strong improvement (>100) of the room temperature photoluminescence intensity was observed for porous GaN layers with a porosity in the 0.4-0.65 range. The characteristics of these porous layers were compared to those obtained with a Si_xN_ynanomask. Furthermore, the regrowth of p-type GaN on light emitting diode structures made porous by using either an AlN or a Si_xN_ynanomask were compared.

Determination of the direct bandgap value in In4Se3thin films

The value and the nature of the bandgap of In₄Se₃are still not well defined, with a large spread of the experimental data between 0.42 and 1.68 eV and an uncertain nature, predicted to be indirect byab initioband structure calculations. Here we report on the optical transmission and photoluminescence (PL) performed in In₄Se₃thin films grown by coevaporation on (0001)-oriented sapphire wafers. The quality of the polycrystalline layers allows the first detection of the excitonic-like transition in the optical absorption of this compound at low temperature. The PL detected under weak laser excitation shows a bound exciton emission at 0.75 eV. Strong laser irradiation reveals a quadratic dependence of the PL intensity on the optical excitation, which demonstrates a stimulated emission at 0.79 eV in relation with an exciton-exciton scattering process. On the basis of a reasonable estimate of the exciton energy, equal to10-15meV, we evaluate the direct bandgap of In₄Se₃to0.82±0.01eV at low temperature.

Decoherence of V[Formula: see text] spin defects in monoisotopic hexagonal boron nitride

Spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of flexible two-dimensional quantum sensing platforms. Here we rely on hBN crystals isotopically enriched with either 10B or 11B to investigate the isotope-dependent properties of a spin defect featuring a broadband photoluminescence signal in the near infrared. By analyzing the hyperfine structure of the spin defect while changing the boron isotope, we first confirm that it corresponds to the negatively charged boron-vacancy center ([Formula: see text]). We then show that its spin coherence properties are slightly improved in 10B-enriched samples. This is supported by numerical simulations employing cluster correlation expansion methods, which reveal the importance of the hyperfine Fermi contact term for calculating the coherence time of point defects in hBN. Using cross-relaxation spectroscopy, we finally identify dark electron spin impurities as an additional source of decoherence. This work provides new insights into the properties of [Formula: see text] spin defects, which are valuable for the future development of hBN-based quantum sensing foils.

Safety of sequential immune checkpoint inhibitors after prior immune therapy

BACKGROUND

The use of immune checkpoint inhibitors (ICI) has transformed cancer treatment. Subsequent ICI use has become increasingly common following disease progression. We aim to evaluate the safety and tolerability of the sequential ICI treatment modality.

METHODS

Retrospective review of confirmed carcinoma from January 2014 to December 2018. Patients were categorized into "initial ICI arm" and "sequential ICI arm" defined as patients receiving single, dual or chemo-immunotherapy ICI following an initial ICI regimen. Primary outcome was the development of a new or recurrent immune related adverse event (irAE) during sequential therapy. Secondary outcomes were the number of cycles prior to the development of irAE and grade of irAE.

RESULTS

A total of 483 patients received ICI during the timeframe. Of those, 22 patients received sequential ICI. The diagnoses included ten lung cancer, seven melanoma, four renal cell carcinoma and one bladder cancer. 16 patients received single agent ICI following the initial ICI, three patients received dual ICI following the initial ICI, one patient received chemotherapy-immunotherapy following initial ICI, and two patients received chemo-immunotherapy after dual ICI. Four patients developed new irAE and one patient developed the same irAE on sequential treatment. A higher proportion of patients experienced grade 3 irAE in the sequential arm compared to the initial ICI arm (p = 0.03). No statistical difference was found between the development of irAE and the number of cycles prior to development of irAE in either treatment groups (p = 0.5).

CONCLUSION

Our data shows overall safety of sequencing ICI when close monitoring was employed.

Flat Bands and Giant Light-Matter Interaction in Hexagonal Boron Nitride

Dispersionless energy bands in k space are a peculiar property gathering increasing attention for the emergence of novel electronic, magnetic, and photonic properties. Here, we explore the impact of electronic flat bands on the light-matter interaction. The van der Waals interaction between the atomic layers of hexagonal boron nitride induces flat bands along specific lines of the Brillouin zone. The macroscopic degeneracy along these lines leads to van Hove singularities with divergent joint density of states, resulting in outstanding optical properties of the excitonic states. For the direct exciton, we report a giant oscillator strength with a longitudinal-transverse splitting of 420 meV, a record value, confirmed by our ab initio calculations. For the fundamental indirect exciton, flat bands result in phonon-assisted processes of exceptional efficiency, that compete with direct absorption in reflectivity, and that make the internal quantum efficiency close to values typical of direct band gap semiconductors.

Insurance data of patients receiving sequential immune checkpoint inhibitors: A single center experience

e18835

Background: Immune checkpoint inhibitors (ICI) up regulate T cell activity promoting tumor cell death and revolutionized modern oncology. The use and number of indications for ICI is growing at an unprecedented speed. Combination and sequential ICI therapies have been shown to be beneficial in certain types of cancer. There is no significant data to support non-FDA approved sequential use of ICI when patients develop toxicities or progression which could result in a significant financial burden on the patient and the health care system. We conducted a retrospective review of cancer patients receiving ICI at our institution and evaluated the insurance status of these patients who received sequential ICI. Methods: We retrospectively reviewed Oncology patients’ charts who received ICI between January 1, 2014 to December 18, 2018. We identified patients receiving sequential ICI, to be defined as patients who received a second ICI, following an initial ICI therapy. Insurance status was evaluated for patients receiving sequential therapy. Commercial insurance was defined as either private or non-Medicare/Medicaid. Results: Out of total 437 patients receiving ICI, 15 patients received sequential ICI. 11 patients were transitioned to a secondary ICI following disease progression (73%), three had immune related adverse events and one was switched per standard of care. Nine patients (60%) had commercial insurance and six patients (40%) had medicare/medicaid. Of those, one had urothelial carcinoma and was switched to pembrolizumab from atezolizumab due to disease progression. One patient had melanoma and received nivolumab following ipilimumab when data from the CHECKMATE 238 were published. Three patients with melanoma were transitioned from ipilimumab to nivolumab, two had disease progression and one had autoimmune dermatitis. Two patients had lung adenocarcinoma and were switched from nivolumab to pembrolizumab due to disease progression. One patient had small cell lung cancer and received pembrolizumab following nivolumab due to disease progression. One patient had squamous cell lung cancer and was switched to pembrolizumab from nivolumab following disease progression. Conclusions: With the rapid growth and advancement of ICI indications, there is limited data available on the benefits of sequential ICI to our patients in the clinical setting. We report a small percentage of oncology patients receiving sequential treatment with or without FDA approval and explore their insurance status. Majority of our patients who transitioned to a second ICI due to progression had commercial insurance. Larger prospective studies are needed to evaluate sequential ICI efficacy and tolerability and cost effectiveness.

Strongly Confined Excitons in GaN/AlN Nanostructures with Atomically Thin GaN Layers for Efficient Light Emission in Deep-Ultraviolet

Fascinating optical properties governed by extremely confined excitons have been so far observed in 2D crystals like monolayers of transition metal dichalcogenides. These materials, however, are limited for production by epitaxial methods. Besides, they are not suitable for the development of optoelectronics for the challenging deep-ultraviolet spectral range. Here, we present a single monolayer of GaN in AlN as a heterostructure fabricated by molecular beam epitaxy, which provides extreme 2D confinement of excitons, being ideally suited for light generation in the deep-ultraviolet. Optical studies in the samples, supplemented by a group-theory analysis and first-principle calculations, make evident a giant enhancement of the splitting between the dark and bright excitons due to short-range electron-hole exchange interaction that is a fingerprint of the strongly confined excitons. The practical significance of our results is in the observation of the internal quantum yield of the room-temperature excitonic emission as high as ∼75% at 235 nm.

InSe as a case between 3D and 2D layered crystals for excitons

InSe is a promising material in many aspects where the role of excitons is decisive. Here we report the sequential appearance in its luminescence of the exciton, the biexciton, and the P-band of the exciton-exciton scattering while the excitation power increases. The strict energy and momentum conservation rules of the P-band are used to reexamine the exciton binding energy. The new value ≥20 meV is markedly higher than the currently accepted one (14 meV), being however well consistent with the robustness of the excitons up to room temperature. A peak controlled by the Sommerfeld factor is found near the bandgap (~1.36 eV). Our findings supported by theoretical calculations taking into account the anisotropic material parameters question the pure three-dimensional character of the exciton in InSe, assumed up to now. The refined character and parameters of the exciton are of paramount importance for the successful application of InSe in nanophotonics.

Direct band-gap crossover in epitaxial monolayer boron nitride

Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.

Integrative Therapies During and After Breast Cancer Treatment: ASCO Endorsement of the SIO Clinical Practice Guideline

Purpose

The Society for Integrative Oncology (SIO) produced an evidence-based guideline on use of integrative therapies during and after breast cancer treatment that was determined to be relevant to the American Society of Clinical Oncology (ASCO) membership. ASCO considered the guideline for endorsement.

Methods

The SIO guideline addressed the use of integrative therapies for the management of symptoms and adverse effects, such as anxiety and stress, mood disorders, fatigue, quality of life, chemotherapy-induced nausea and vomiting, lymphedema, chemotherapy-induced peripheral neuropathy, pain, and sleep disturbance. Interventions of interest included mind and body practices, natural products, and lifestyle modifications. SIO systematic reviews focused on randomized controlled trials that were published from 1990 through 2015. The SIO guideline was reviewed by ASCO content experts for clinical accuracy and by ASCO methodologists for developmental rigor. On favorable review, an ASCO Expert Panel was convened to review the guideline contents and recommendations.

Results

The ASCO Expert Panel determined that the recommendations in the SIO guideline—published in 2017—are clear, thorough, and based on the most relevant scientific evidence. ASCO endorsed the guideline with a few added discussion points.

Recommendations

Key recommendations include the following: Music therapy, meditation, stress management, and yoga are recommended for anxiety/stress reduction. Meditation, relaxation, yoga, massage, and music therapy are recommended for depression/mood disorders. Meditation and yoga are recommended to improve quality of life. Acupressure and acupuncture are recommended for reducing chemotherapy-induced nausea and vomiting. Acetyl-l-carnitine is not recommended to prevent chemotherapy-induced peripheral neuropathy because of a possibility of harm. No strong evidence supports the use of ingested dietary supplements to manage breast cancer treatment–related adverse effects. Additional information is available at: www.asco.org/supportive-care-guidelines .

Isotope engineering of van der Waals interactions in hexagonal boron nitride

Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes (¹⁰B and ¹¹B) compared to those with the natural distribution of boron (20 at% ¹⁰B and 80 at% ¹¹B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in ¹⁰BN than in ¹¹BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

The microstructure, local indium composition and photoluminescence in green-emitting InGaN/GaN quantum wells

In this work, we analyse the microstructure and local chemical composition of green-emitting In_x Ga_1-x N/GaN quantum well (QW) heterostructures in correlation with their emission properties. Two samples of high structural quality grown by metalorganic vapour phase epitaxy (MOVPE) with a nominal composition of x = 0.15 and 0.18 indium are discussed. The local indium composition is quantitatively evaluated by comparing scanning transmission electron microscopy (STEM) images to simulations and the local indium concentration is extracted from intensity measurements. The calculations point out that the measured indium fluctuations may be correlated to the large width and intensity decrease of the PL emission peak.

Evaluation of carboplatin toxicities and efficacy using different body weight descriptors in the Calvert formula

e14017

Background: Carboplatin dosing is calculated using the Calvert formula that includes glomerular filtration rate (GFR). In practice, GFR is often substituted by creatinine clearance (CrCl) with the Cockcroft-Gault (CG) equation. However, there is no standardization of which body weight descriptors should be utilized. Data suggest use of total body weight (TBW) may overestimate CrCl in overweight patients, while adjusted body weight may better estimate CrCl. The primary objective is to determine the impact of using different weight descriptors (DWD) in place of TBW for carboplatin dosing. Methods: This was a single-center, retrospective cohort study. Patients over 18 who were intended to receive at least 6 cycles of carboplatin with target area under the curve (AUC) of 5 or 6 and paclitaxel 175 to 225 mg/m2 were included. DWD included: adjusted body weight for overweight and obese patients, ideal body weight for normal weight patients and TBW for underweight patients. Primary endpoint was the composite of grade 3 or 4 anemia, thrombocytopenia and neutropenia (hematologic toxicity). Secondary endpoints included individual parameters of the primary endpoint, dose delays, dose reductions, progression-free survival, overall survival and objective response rate. Results: A total of 117 patients were included (DWD: n = 39; TBW: n = 78). Results on survival analysis, anemia and dose reductions are pending. Conclusions: To our knowledge, this is the first evaluation of patient outcomes specifically comparing carboplatin dosing calculations. Although there is a trend toward decreased grade 3 and 4 hematologic toxicities in the DWD group, there is no statistically significant difference in this under powered cohort. However, there was a significant decrease in treatment delays and days of treatment delay (p < 0.001) in the DWD group. Further studies are needed to evaluate the impact of DWD on carboplatin dosing. [Table: see text]

Phonon-Photon Mapping in a Color Center in Hexagonal Boron Nitride

We report on the ultraviolet optical response of a color center in hexagonal boron nitride. We demonstrate a mapping between the vibronic spectrum of the color center and the phonon dispersion in hexagonal boron nitride, with a striking suppression of the phonon assisted emission signal at the energy of the phonon gap. By means of nonperturbative calculations of the electron-phonon interaction in a strongly anisotropic phonon dispersion, we reach a quantitative interpretation of the acoustic phonon sidebands from cryogenic temperatures up to room temperature. Our analysis provides an original method for estimating the spatial extension of the electronic wave function in a point defect.

[Hip fracture, antiplatelet drugs treatment and postoperative complications]

OBJECTIVES

To assess the incidence of postoperative complications, blood transfusions and survival at one month, in the old patients operated for hip fracture undergoing chronic treatment with antiplatelet drugs.

MATERIAL AND METHODS

Two hundred twenty three patients operated for hip fracture were studied retrospectively, separated into 3 groups: patients who received acetylsalicylic acid (group I), patients who were given 100mg/day of acetylsalicylic acid or 300mg/day of triflusal (group II) and patients receiving>100mg/day of acetylsalicylic acid, or>300mg/day of triflusal or thienopyridines (group III). Surgery was delayed for 4 days in patients in group III. Demographic, biological, clinical and treatment characteristics, postoperative complications and survival at one month were recorded.

RESULTS

Patients in group III were older and sustain worse general health status. Patients with a higher transfusion requirement were those of group II (73.8%) (P=0.192), who also showed a higher percentage of anaemia on admission. Severe cardiovascular complications were experienced by 5.4% of group III patients, 4.8% of group II patients and 2.1% of group I patients. Patients from group III presented a significant amount of respiratory complications (P=0.007).

CONCLUSIONS

Our results suggest that delaying surgery for 4 days in patients treated with clopidogrel can be associated to an increase in postoperative respiratory complications and severe adverse cardiovascular events, without increasing the tranfusional index, hospital stay, mortality, and without complications related to neuraxial anaesthesia.

High quality factor nitride-based optical cavities: microdisks with embedded GaN/Al(Ga)N quantum dots

We compare the quality factor values of the whispering gallery modes of microdisks (μ-disks) incorporating GaN quantum dots (QDs) grown on AlN and AlGaN barriers by performing room temperature photoluminescence (PL) spectroscopy. The PL measurements show a large number of high Q factor resonant modes on the whole spectrum, which allows us to identify the different radial mode families and to compare them with simulations. We report a considerable improvement of the Q factor, which reflects the etching quality and the relatively low cavity loss by inserting QDs into the cavity. GaN/AlN QDs-based μ-disks show very high Q values (Q>7000) whereas the Q factor is only up to 2000 in μ-disks embedding QDs grown on the AlGaN barrier layer. We attribute this difference to the lower absorption below bandgap for AlN barrier layers at the energies of our experimental investigation.

Recombination Dynamics in Nitride Quantum Boxes and Quantum Wells for Colors Ranging from the UV to the Red

Time-resolved photoluminescence experiments at varying temperature are performed on a series of InxGa1−xN/GaN quantum well and quantum box samples of similar compositions (0.15 < x < 0.20). The results are analyzed by using envelope-function calculations of transition energies and oscillator strengths, accounting for internal electric fields. The respective influences of localization and electric fields on radiative and nonradiative lifetimes and on the Stokes shift are deduced. The results indicate that the spatial extension of localization centers is much smaller than the size of the quantum boxes (∼10 × 3 nm, typically). The room-temperature radiative efficiency of both quantum well and quantum box samples is enhanced by replacing the topmost GaN barrier by an AlGaN one.

Growth Kinetics and Structural Quality in GaN Epitaxy by Low Pressure MOVPE

GaN epilayers have been grown using low pressure MOVPE (76 Torr) onto (0001) sapphire substrates. Triethylgallium (TEGa) and Ammonia (NH3) were used as precursors. The growth rate has been determined versus growth parameters. The growth rate versus NH3 flow displays a rather unusual behavior, in particular at low growth temperature (buffer layer), where the growth rate decreases strongly when the NH3 flow increases. A growth mechanism involving a competitive adsorption step onto the surface is proposed, and results in a strong dependence of the growth rate on the V/III ratio.

The structural quality of the layers has been assessed by X-ray diffraction versus the growth parameters, and will be reported here. A substrate nitridation step, prior to buffer layer deposition has been introduced in our growth process. The effect of substrate nitridation on the structural and optical properties of the epilayers is studied and we propose an optimized pre-treatment for the MOVPE growth of GaN onto (0001) sapphire substrates.

Radiative And Nonradiative Relaxation Of Excitons In GaN

We report on investigations of the excitonic quantum efficiency in GaN epilayers as function of buffer layer thickness, buffer layer material, sample thickness and residual oxygen content. These values are compared to that of GaN bulk material. The quantum efficiency of the free excitons rises with increasing buffer layer thickness, increasing sample thickness and decreasing residual oxygen content. The influence of oxygen on the quantum efficiency is stronger than that of the buffer layer thickness. Additionally, the homoepitaxial growth of GaN shows higher quantum efficiencies than the growth with an AIN buffer layer. In general, the observed quantum efficiencies in GaN epilayers are below 20% indicating the strong impact of nonradiative relaxation and recombination processes in the excitonic range. Only, GaN bulk material shows quantum efficiencies of 25 % for the free A-exciton XA and of 50 % for the donor-bound exciton complex D0,X).

Influence of Surface Defects on the Characteristics of GaN Schottky Diodes

We have studied the fabrication of Pt/Au Schottky diodes on n-type GaN. We show that the electrical characteristics of the diodes are strongly dependent on the surface chemical treatment before the metal deposition. Lowest leakage currents were obtained by the use of a HC1 solution. We also show that annealing the diode at a moderate temperature (400°C) leads to reduced reverse currents. In order to explain these results, we measured the density of deep levels in the Schottky diode depletion region before and after the annealing process. We did not observe any significant difference in the bulk density of defects due to the anneal. We also studied the temperature dependence of the reverse currents and found a low activation energy. Our results are interpreted in terms of electrical defects at the metal-GaN surface.

Do patients with recurrent ovarian cancer benefit from relative tumor reduction? Results from a prospective study

e16541

Background: Primary cytoreduction is the cornerstone in the management of epithelial ovarian cancer (OC). However, the roles of salvage surgery and of tumor reduction are still discussed controversially. The present study was conducted to assess the impact of secondary tumor reduction surgery on progression-free survival and on overall survival. Methods: Between September 2000 and April 2006, 177 consecutive patients (pts) with a first relapse of OC underwent secondary tumor reduction surgery at our department. The achieved tumor reduction was categorized as 1/5 (20% tumor debulked), 2/5 (40%), 3/5 (60%), 4/5 (80%), or 5/5 (macroscopic tumor-free) and the maximal tumor diameter was also denoted (tumor free, < 1cm, ≥ 1cm). Results: The median age was 56 years (95% CI: 23–83), median follow-up was 10.8 months (95% CI: 1–65). In 79 pts (44.6%) complete macroscopic tumor resection was achieved (median overall survival (OAS) 60.6 months, 21.3–99.8 and median progression-free survival (PFS) 14.9 months, 11.7–18, p < 0.001). In 56 pts (31.6%) 4/5 of the tumor was removed (OAS 15.6 months, 10.3–20.8 and PFS 9 months, 7.2–10.7, p < 0.001), in 13 (7.3%) 3/5 (OAS 21.7 months, no interval and PFS 12 months, 0.0–24.5, p < 0.001) and in 7 (4%) each 2/5 tumor reduction (OAS was 14.2 months, 4.1–24.2 and PFS 11 months, 5.9–16, p < 0.001) and if 1/5 tumor reduction was achieved OAS was 11.1 months, 2–20.1 and PFS 7 months, 2.5–11.4, p < 0.001. Fifteen pts (8.5%) had a bulky unresected disease (OAS 4.7 months, 1.0–8.3 and PFS of 3.7 months, 0–7.6, p < 0.001). From these 98 (55.4%) pts without complete macroscopic tumor resection, 46 were left with <1cm tumor diameter (OAS 17.2 months, 13–21.4 and PFS 9 months, 7.4–10.6 p < 0.001) and 52 with ≥1cm tumor diameter (OAS 8.7 months, 4.2–13.2 and PFS 7 months, 5.8–8.2 p < 0.001). All in all, the median postoperative survival for pts with tumor residuals and any tumor reduction (4/5, 3/5, 2/5. and 1/5 tumor reduction) were better when compared to pts with no tumor reduction (24.8 months vs. 4.7, p < 0.001). Conclusions: Our data demonstrate a significant benefit for salvage surgery if a macroscopic complete tumor resection can be achieved. We could not see any effect of relative tumor reduction on PFS or OAS.

No significant financial relationships to disclose.

Efficacy and pharmacogenomic correlation of the combination of oxaliplatin and paclitaxel in first line advanced non-small cell lung cancer (NSCLC). Preliminary results of the Spanish Lung Cancer Group (SLCG) 0103 phase II trial

7122

Background: Ox is an attractive platinum analogue that has not been fully explored in NSCLC. We tested the combination of ox/pac as first-line therapy in NSCLC. We also assessed single nucleotide polymorphisms (SNPs) in several DNA repair genes (XRCC1 Arg399Gln, XRCC3 Met241Thr, XPD Lys751Gln and XPD Asp312Asn) and correlated the results with outcome in these patients (p). Methods: 68 stage IIIB (pleural effusion) and IV NSCLC p received up to 6 cycles of p 200 mg/m2 on day 1 plus ox 130 mg/m2 on day 2 every 21 days. Response was assessed after the third and sixth cycles. SNPs were determined by TaqMan assay in peripheral blood extracted at baseline Results: p characteristics: median age 62; 82% male; performance status 0, 54.5%; adenocarcinoma 48%; CNS metastases (mets), 15%, liver mets, 17%. 259 cycles delivered. Grade (G) 3–4 toxicity profile: neutropenia 11%; febrile neutropenia 8%; neurosensory (G3) 5%; asthenia (G3) 8%; diarrhea (G3) 5%. Laryngodysesthesia was observed in 1 p. There were 2 deaths due to neutropenic fever. In 52 evaluable p, overall response rate was 48% (PR 46%, CR 2%, SD 6%, PD 21%). Median time to progression was 4.4 months (m) (95% CI, 2.9–5.9 m). Median survival was 7.9 m (95% CI, 5.5–10.3 m). Conclusions: The combination of ox/pac offers similar results to other platinum-based regimens with an acceptable different toxicity profile and without a significant increase in neurotoxicity. Final data on response, time to progression and survival according to SNPs will be presented.

No significant financial relationships to disclose.

Photon BLOCH oscillations in porous silicon optical superlattices

We report the first observation of oscillations of the electromagnetic field in an optical superlattice based on porous silicon. These oscillations are an optical equivalent of well-known electronic Bloch oscillations in crystals. Elementary cells of our structure are composed by microcavities whose coupling gives rise to the extended collective modes forming optical minigaps and minibands. By varying thicknesses of the cavities along the structure axis, we have created an effective electric field for photons. A very high quality factor of the confined optical state of the Wannier-Stark ladder may allow lasing in porous silicon-based superlattices.

Do fibrinolytic proteins of human bile derive exclusively from gall bladder?

BACKGROUND

In this study we addressed the issue of whether fibrinolytic proteins are presented in gall bladder bile only or in choledochus bile as well.

MATERIAL AND METHODS

Gall bladder bile was obtained from 20 patients (Group I) undergoing laparoscopic cholecystectomy. Bile from common bile duct was aspirated after insertion Kehr drainage from 9 patients (Group II). The concentrations of t-PA, u-PA, PAI-1 and PAI-2 were measured by ELISA.

RESULTS

We have shown that in cholecystectomized patients fibrinolytic proteins can be detected in bile both from gall bladder and from choledochus. Mean concentrations of t-PA, u-PA, PAI-1 were lower in Group II (5.69 ng/ml vs 15.7; 0.46 ng/ml vs 0.7; 16.82 ng/ml vs 26.16 ng/ml) or nearly equal for PAI-2 (343.53 ng/ml vs 341.02). All differences were insignificant (p > 0.05).

CONCLUSIONS

Based on these results we concluded that the entire biliary tree produces the fibrinolytic proteins thus this production is not restricted to the gall bladder as it was earlier reported [1].

Accuracy of t-PA, u-PA, PAI-1 and PAI-2 estimation in human bile by ELISA kits

The aim of this study was to establish the accuracy of determination of fibrinolytic proteins in human bile using commercial kits.

MATERIAL AND METHOD

Gall bladder bile was obtained from patient undergoing laparoscopic cholecystectomy. The concentrations of tissue plasminogen activator (tPA), urokinase (uPA) and plasminogen activator inhibitor-1 (PAI-1) and inhibitor-2 (PAI-2) in bile were measured by enzyme linked immunoassay. Afterwards we conducted so called 'recovery test'.

RESULTS

Recovery percents of t-PA, u-PA, PAI-1, PAI 2 were very high i.e. 91.94, 94.07, 93.95, 91.2. We concluded that human fibrinolytic proteins in bile could be detected very accurately using commercial kits.

Phase I-II trial of intensification of the MAID regimen with support of lenograstim (rHuG-CSF) in patients with advanced soft-tissue sarcoma (STS)

This study was conducted to determine the maximum tolerated dose of an intensified MAID (mesna, adriamycin, ifosfamide, dacarbazine) regimen with the support of lenograstim in patients with advanced soft tissue sarcomas. Following 1 cycle of MAID at the standard dose, four patients were to be treated at each of five dosage levels: +25%, +45%, +65%, +85%, +100%. Sixteen patients were treated. Because there were no significant differences in hematologic toxicity between patients receiving lenograstim 5 or 10 microg/kg/day (levels 1-5 and 1-10), the data were pooled for comparison with level 2. The median duration of absolute neutrophil count < 0.5 x 10(9)/l was 3 days at level 1 and 7 days at level 2 (p < 0.01). The median platelet nadir was 25 x 10(9)/l at level 1 and 10 x 10(9)/l at level 2 (p < 0.01). The median duration of toxicity-related hospitalization was 3.5 days and 11 days at levels 1 and 2, respectively, (p < 0.001). Mucositis > or = grade III occurred after 3/29 cycles at level 1 and 10/15 cycles at level 2 (p < 0.001). After 4 cycles at level 1, 8/8 patients still had performance status scores < or = 2, and only 4/8 had performance status scores < or = 2 after the second cycle at level 2. Lenograstim enabled an increase of 25% of the MAID regimen. At higher dose levels, severe mucositis and deterioration in performance status were dose limiting.