Coherent light scattering from a telecom C-band quantum dot.

Quantum networks have the potential to transform secure communication via quantum key distribution and enable novel concepts in distributed quantum computing and sensing. Coherent quantum light generation at telecom wavelengths is fundamental for fibre-based network implementations, but Fourier-limited emission and subnatural linewidth photons have so far only been reported from systems operating in the visible to near-infrared wavelength range. Here, we use InAs/InP quantum dots to demonstrate photons with coherence times much longer than the Fourier limit at telecom wavelength via elastic scattering of excitation laser photons. Further, we show that even the inelastically scattered photons have coherence times within the error bars of the Fourier limit. Finally, we make direct use of the minimal attenuation in fibre for these photons by measuring two-photon interference after 25 km of fibre, demonstrating finite interference visibility for photons emitted about 100,000 excitation cycles apart.

Multiple Reactivations of Viral Infections Followed by Cerebral Toxoplasmosis After Allogeneic Hematopoietic Stem Cell Transplantation in an Adolescent With Ph(+) Acute Lymphoblastic Leukemia: A Case Report.

After allogeneic hematopoietic stem cell transplantation (allo-HSCT), especially from an unrelated donor, infectious complications are frequent and severe, sometimes with fatal outcomes. Despite using highly sensitive molecular techniques for close monitoring in the early post-transplant period for early diagnosis, not every viral infection or reactivation can be detected adequately early, even with highly sensitive methods. Particularly after toxic and deeply immunosuppressive treatment, multiple infections or reactivations, uncommon infections, or infections in unusual locations can occur. Here, we present a case of multiple viral infections or reactivations and cerebral toxoplasmosis in a 17-year-old youth with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) treated with allo-HSCT who suffered multiple viral infections followed by cerebral toxoplasmosis.

A quantum light-emitting diode for the standard telecom window around 1,550 nm.

Single photons and entangled photon pairs are a key resource of many quantum secure communication and quantum computation protocols, and non-Poissonian sources emitting in the low-loss wavelength region around 1,550 nm are essential for the development of fibre-based quantum network infrastructure. However, reaching this wavelength window has been challenging for semiconductor-based quantum light sources. Here we show that quantum dot devices based on indium phosphide are capable of electrically injected single photon emission in this wavelength region. Using the biexciton cascade mechanism, they also produce entangled photons with a fidelity of 87 ± 4%, sufficient for the application of one-way error correction protocols. The material system further allows for entangled photon generation up to an operating temperature of 93 K. Our quantum photon source can be directly integrated with existing long distance quantum communication and cryptography systems, and provides a promising material platform for developing future quantum network hardware.

The relationship between selected parameters of a cephalometric analysis determining the vertical morphology of facial skeleton and bite force.

BACKGROUND: There are few studies devoted to an assessment of the relation between bite force and detailed results of cephalometric analysis that determine craniofacial structure. The purpose of the study was to assess the correlation between the selected criteria determining the craniofacial structure and bite force in patients with normal and increased vertical relation of the bases of jaws and skull. MATERIALS AND METHODS: The study material included 120 patients, aged between 7 and 17 years, who presented for examination and possible orthodontic treatment. The patients were divided into a study group and a control group. The basis of this division were ML-NL and ML-NSL angles, according to Segner's and Hasund's analysis standards, respectively: above 27° and above 30° in the study group, and 20.0 ± 7.0° and 28.0 ± 5.0° in the control group. Bite force was tested using a digital dynamometer calibrated in Newtons. The measurement was performed at the level of the first permanent molars. Vertical relations were assessed using the following cephalometric measurements: ML-NSL, ML-NL, NL-NSL, N-Me, Sp-Me, SpMe:NMe, ms-NL, SGo:NMe. RESULTS: Bite force was not found to be dependent on the lower anterior face height (Sp-Me), the ratio of anterior lower to total anterior face height (SpMe:NMe), and NL-NSL angle both in patients with abnormal and normal relations of bases of jaws and skull. Although statistically non-significant, the average mean and maximum bite force values were found to be lower in patients with high-angle relation of bases of jaws and skull than in subjects with normal relation of bases of jaws and skull. CONCLUSIONS: Among the selected parameters determining the vertical craniofacial structure, the rear height of the alveolar process (ms-NL) exerts the greatest influence on bite force in both patients with increased and normal vertical relation of bases of jaws and skull, and with an increase in the value of ms-NL, bite force is reduced.

Immunosuppression in Dogs During Mammary Cancer Development.

Cancer immunosuppression that facilitates tumor progression and metastasis evolves by development of an immunosuppressive network. The aim of this study was to assess this network in dogs with benign or malignant tumors with or without confirmed metastasis. The authors showed that the number of various T cell subpopulations was constant during tumor development; however the number of regulatory T cells (Tregs) was significantly higher in tumor-bearing dogs than in healthy individuals. The number of myeloid-derived suppressor cells (MDSCs) and their p-STAT3 expression (which is a negative regulator of hematopoiesis and regulates VEGF expression) were higher in cancer patients than in control dogs, however their number increased significantly in late-stage cancer patients. Canine mammary carcinomas with confirmed metastases to either lymph nodes or internal organs had greater MDSCs and Treg infiltration than benign mammary tumors or malignant mammary tumors for which metastases had not been detected. Similarly, expression of p-STAT3 and VEGF-C was the highest in tumors with confirmed metastases. This research shows changes occurring in the blood (n = 30 patients) and tumor tissue of patients (n = 100) during canine mammary tumor development. The findings should be considered preliminary because of the small number of samples. Nonetheless, the findings suggest that a high level of Tregs and MDSCs as well as high expression of p-STAT3 and VEGF-C may significantly contribute to mammary tumor progression and metastasis in dogs.

Craniofacial structure in patients with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is characterised by at least five 10-s episodes of apnoea or markedly shallow breathing per 1 h of sleep, which can lead to severe, sometimes life-threatening complications. It is essential to determine the specific features of the affected patients' craniofacial structure, thus enabling their allocation to risk groups. The aim of the study was to assess the craniofacial structure in OSA patients, comparing the findings with Hasund's and Segner's cephalometric normal values. In addition, the sagittal dimensions of the upper airways, measured at two levels, were compared to McNamara's normal values. MATERIALS AND METHODS: The study covered 41 patients diagnosed polysomno-graphically with OSA. Lateral cephalograms with cephalometric analysis and the measurements of the upper and lower sagittal dimensions of the upper airways were taken for each patient. RESULTS: The only feature of the patents' facial skeleton that significantly diverged from the normal range was the SNB angle (p = 0.004). Other angles, i.e. SNA, ANB, NL/NSL, NL/ML and NSL/ML, were not significantly different from normal. The average upper cross-sectional area of the upper airways was 10.4 mm; in 97.6% patients, this measurement was below McNamara's normal values. In the majority of patients (75.6%), the average lower sagittal dimension of the upper airways (10.4 mm) was also below the normal. CONCLUSIONS: Mandibular retrognathia, manifested by the reduced SNB angle, and the narrowed upper and lower sagittal dimensions of the upper airways can be considered one of OSA prognostic factors.

The relationship between facial skeleton morphology and bite force in people with a normal relation of the bases of jaws and skull.

BACKGROUND: Better knowledge on the relationship between craniofacial structure and bite force may serve as a reference point for prophylactic and therapeutic activities targeted at developmental age patients. The aim of the study was to assess the correlation between facial skeletal morphology and bite force. MATERIALS AND METHODS: The study included 54 subjects aged 7-16 years with a normal relation of the bases of jaws and skull, according to Segner's and Hasund's analysis standards (ML-NL and ML-NSL angles values were 20.0 ± 7.0° and 28.0 ± 5.0°, respectively). The study group included patients who volunteered to diagnosis and possible orthodontic treatment. Bite force was tested with a digital dynamometer calibrated in Newtons. The measurement was performed at the level of the first permanent molars. Cephalometric analysis was based on lateral cephalometric radiographs. The vertical relations were assessed using the following measurements: ML-NSL, ML-NL, NL-NSL, N-Me, Sp-Me, SpMe:NMe, ms-NL, SGo:NMe. RESULTS: Bite force does not depend on the following factors: lower anterior face height (Sp-Me), lower anterior face height to total anterior face height ratio (SpMe:NMe), posterior to anterior face height ratio (SG0:NMe), and the value of ML-NL, ML-NSL and NL-NSL angles. CONCLUSIONS: The posterior height of the maxilla alveolar process (ms-NL) exerts the greatest influence on bite force in people with a normal relation of the bases of jaws and skull: with an increase in ms-NL value bite force is reduced.

Bite force and its correlation with long face in children and youth.

BACKGROUND: Bite force is one of the indicators of proper functioning of the stomatognathic system, and its value may have diagnostic significance in disorders of the musculoskeletal system of facial bones. The aim of the study was to evaluate the relationship between gender and age, and bite force in patients with high--angle vertical relationship of jaws and cranial bases. MATERIALS AND METHODS: The study group comprised 66 subjects aged 7-17 years, in whom the mandibular jaw base line and maxillary jaw-base line (ML-NL) angles were greater than 27° and the mandibular jaw-baseline and the anterior cranial base line (ML-NSL) above 33°, and a control group (n = 54) aged 7-16 years, in which the ML-NL angles were 20.0 ± 7.0° and ML-NSL 28.0 ± 5.0°. For measuring the bite force, a Japanese digital dynamometer Imada type ZPS-LM--2000N was used. RESULTS: In the study group no statistically significant correlation between the bite force and gender was shown, and in the control group the average bite force on the right side was significantly different for boys and girls, whereas for boys it was higher. In the study group the relationship between the age and average and maximum bite force on the right and left side was significant. In the group of people with a high-angle relationship of bases of jaws and skull no statistically significant correlation between the bite force and gender was shown. CONCLUSIONS: The was no effect of gender on the bite force in all subjects up to 18 years of age, both in patients with a high-angle and normal relationship of bases of jaws and skull. In people with a high-angle relationship of bases of jaws and cranium masticatory forces increase with age.

Quantum teleportation of laser-generated photons with an entangled-light-emitting diode.

Quantum teleportation can transfer information between physical systems, which is essential for engineering quantum networks. Of the many technologies being investigated to host quantum bits, photons have obvious advantages as 'pure' quantum information carriers, but their bandwidth and energy is determined by the quantum system that generates them. Here we show that photons from fundamentally different sources can be used in the optical quantum teleportation protocol. The sources we describe have bandwidth differing by a factor over 100, but we still observe teleportation with average fidelity of 0.77, beating the quantum limit by 10 standard deviations. Furthermore, the dissimilar nature of our sources exposes physics hidden in previous experiments, which we also predict numerically. These phenomena include converting qubits from Poissonian to Fock statistics, quantum interference, beats and teleportation for spectrally non-degenerate photons, and acquisition of evolving character following teleportation of a qubit.

Phototherapy with low-level laser influences the proliferation of endothelial cells and vascular endothelial growth factor and transforming growth factor-beta secretion.

The healing process and the angiogenesis associated with it, is a very important but currently poorly understood area. Low level laser therapy (LLLT) has been reported to modulate the process of tissue repair by stimulation of cellular reaction such as migration, proliferation, apoptosis and cellular differentiation. The aim of this work was to evaluate the influence of laser radiation in the range of visible and infrared light on the proliferation of vascular endothelial cells in vitro and the secretion of angiogenic factors: vascular endothelial growth factor (VEGF)-A and transforming growth factor (TGF)-ß. Vascular human endothelial cells (Ecs) were exposed to radiation with laser beam of the wavelengths: 635 nm (1.875 mW/cm²) and 830 nm (3.75 mW/cm²). Depending on the radiation energy density, the experiment was conducted in four groups : I) the control group (no radiation, 0 J/cm²); II) 635 nm - the energy density was 2 J/cm²; III) 635 nm - 4 J/cm²; IV635 nm - 8 J/cm², II) 830 nm - the energy density was 2 J/cm²; III) 830 nm - 4 J/cm²; IV) 830 nm - 8 J/cm². The proliferation and concentration of VEGF-A and TGF-ß were examined. LLLT with wavelength 635 nm increases endothelial cell proliferation. Significant increase in endothelial cell proliferation and corresponding decrease in VEGF concentration may suggest the role for VEGF in this process. The wavelength of 830 nm was associated with a decrease in TGF-ß secretion.

Effect of rugby training on blood antioxidant defenses in able-bodied and spinal cord injured players.

STUDY DESIGN: A cross-sectional study with comparison group. OBJECTIVES: To examine the effect of rugby training on the blood antioxidant capacity in able-bodied and wheelchair rugby players with tetraplegia. SETTING: Poland. METHODS: Four groups of subjects participated in the study: sedentary able-bodied males (group SA, n=19), sedentary males with tetraplegia (group ST, n=10), able-bodied rugby players (group RA, n=22) and wheelchair rugby players with tetraplegia (group RT, n=14). The activities of superoxide dismutase (SOD), glutathione reductase (GR) and catalase (CAT) were determined in erythrocyte hemolysates, whereas glutathione peroxidase (GPX) activity was determined in whole-blood hemolysates. Concentrations of total antioxidant status (TAS) was determined in plasma. RESULTS: SOD activity was significantly higher in the group SA compared with group ST and group RA. No significant differences occurred within the tetraplegic groups: RT and ST. Resting CAT and GPX activities were significantly higher in both the groups of rugby players than in the respective group of sedentary males. There were no differences in GR activity among all the studied groups. Plasma TAS concentration was higher in both the groups of able-bodied males compared with the respective groups of tetraplegics. The present study is the first to conduct an evaluation of wheelchair rugby training-induced adaptations to oxidative stress in individuals with tetraplegia. CONCLUSION: Adaptive response to training was similar in both able-bodied and wheelchair rugby players, and it was characterized by increased erythrocyte CAT and GPX activities in resting conditions improving resistance to oxidative stress.

Fast optical preparation, control, and readout of a single quantum dot spin.

We propose and demonstrate the sequential initialization, optical control, and readout of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole pair. Optical control is observed as a coherent Rabi rotation between the hole and charged-exciton states, which is conditional on the initial hole spin state. The spin-selective creation of the charged exciton provides a photocurrent readout of the hole spin state.

Nuclear spin switch in semiconductor quantum dots.

We show that by illuminating an InGaAs/GaAs self-assembled quantum dot with circularly polarized light, the nuclei of atoms constituting the dot can be driven into a bistable regime, in which either a thresholdlike enhancement or reduction of the local nuclear field by up to 3 T can be generated by varying the pumping intensity. The excitation power threshold for such a nuclear spin "switch" is found to depend on both the external magnetic and electric fields. The switch is shown to arise from the strong feedback of the nuclear spin polarization on the dynamics of the spin transfer from electrons to the nuclei of the dot.

CHEK2 is a multiorgan cancer susceptibility gene.

A single founder allele of the CHEK2 gene has been associated with predisposition to breast and prostate cancer in North America and Europe. The CHEK2 protein participates in the DNA damage response in many cell types and is therefore a good candidate for a multisite cancer susceptibility gene. Three founder alleles are present in Poland. Two of these result in a truncated CHEK2 protein, and the other is a missense substitution of an isoleucine for a threonine. We ascertained the prevalence of each of these alleles in 4,008 cancer cases and 4,000 controls, all from Poland. The majority of the common cancer sites were represented. Positive associations with protein-truncating alleles were seen for cancers of the thyroid (odds ratio [OR] 4.9; P=.0006), breast (OR 2.2; P=.02), and prostate (OR 2.2; P=.04). The missense variant I157T was associated with an increased risk of breast cancer (OR 1.4; P=.02), colon cancer (OR 2.0; P=.001), kidney cancer (OR 2.1; P=.0006), prostate cancer (OR 1.7; P=.002), and thyroid cancer (OR 1.9; P=.04). The range of cancers associated with mutations of the CHEK2 gene may be much greater than previously thought.

Environmental health risk of chronic exposure to nitrous oxide in dental practice.

Nitrous oxide may be used to alleviate dental anxiety and to diminish or eliminate dental pain. The benefit of nitrous oxide sedation is a cooperative and satisfied patient. By reducing the patient's perception of pain it allows them to relax and cooperate during dental procedures. However, the dental surgery personnel, chronically exposed to N2O, are at serious risk. The chronic effects of occupational exposure to nitrous oxide have long been the subject of debate. Safety standards have been established in the United States and Europe since many years. The potential detrimental action on the reproductive, neurological, haematological, hepatic and renal systems, plus the possibility of increased cancer risk have been the subject of active research, although absolute occupational effects are still uncertain. To provide a safer work-place for those at risk of exposure to waste anesthetic gases, preventive measures are recommended.

The disposition and metabolism of tetrabromobisphenol-A after a single i.p. dose in the rat.

Tetrabromobisphenol-A (TBBP-A) is used as a reactive (primary use) or an additive flame retardant and as an intermediate in the production of other flame retardants. In our study TBBP-A[14C] was administered intraperitoneally (i.p.) in a single dose of 250 or 1000 mg/kg body weight (about 300 kBq per animal). The level of radioactivity in erythrocytes was 10 times higher than in plasma 72 h after the administration. In all examined tissues the peak level of 14C could be observed within the first hour after the administration, and the highest concentrations were detected in the fat tissue, followed by liver, sciatic nerve, muscles and adrenals. Total excretion in faeces 72 h after the administration was about 51-65% of the dose, whereas in urine it was only 0.3%. About 20% was still retained in the rat organism.

Dentist's hand symptoms and high-frequency vibration.

The paper discusses characteristics of mechanical vibration as well as the mechanisms of vibration syndrome. Analysis of the relationship between the high-frequency vibration and the typical symptoms in the hands of the dentists is presented. Suggestions have been offered on how to limit exposure to vibration in the hands of dentists

Hepatotoxicity of monobromobenzene and hexabromobenzene: effects of repeated dosage in rats.

The aim of the study was to determine whether monobromobenzene (BB) and hexabromobenzene (HBB) administered repeatedly (for 28 days) to female rats resulted in disturbances of heme synthesis. 5-Aminolevulinate dehydratase (ALA-D) and 5-aminolevulinate synthase (ALA-S) activities were slightly changed and the concentration of glutathione increased. The excretion of 5-aminolevulinic acid (ALA-U) in urine after all doses of BB and HBB increased already in the first week. After BB administration, increased excretion of coproporphyrins was detected only at the highest dose. The increased excretion of coproporphyrins following the administration of HBB could be observed already at the lowest dose (15 mg/kg). The excretion of uroporphyrins increased after two higher doses (75 and 375 mg/kg) in the fourth week of exposure. HBB also caused elevation of microsomal P450 level. The data suggest porphyrogenic activity of HBB; whereas in the case of BB we cannot exclude that elevated excretion of ALA-U resulted from kidney impairment.

Work-related vision hazards in the dental office.

Among the numerous threats to the dentist's health there is one relating to the eye. The paper discusses the impact of selected adverse factors on the eye in connection with dental practice in the surgery.

DNA copy number changes in malignant ovarian germ cell tumors.

Malignant ovarian germ cell tumors (OGCTs) include immature teratomas (ITs), dysgerminomas (DGs), endodermal sinus tumors (ESTs), choriocarcinomas, and embryonal carcinomas. Knowledge about the genetic changes associated with malignant OGCT development is sparse. We therefore analyzed 25 OGCTs (12 DGs, 4 ESTs, and 9 ITs) for gains and losses by comparative genomic hybridization. In total, more gains than losses were observed, and the number of alterations ranged from 0-20 per tumor. The average number of changes among DGs, ESTs, and ITs was 10, 6, and 1.4, respectively. The most common changes in DGs were gains from chromosome arms 1p (33%), 6p (33%), 12p (67%), 12q (75%), 15q (42%), 20q (50%), 21q (67%), and 22q (58%); gains of the whole of chromosomes 7 (42%), 8 (42%), 17 (42%), and 19 (50%); and losses from 13q (58%). Two of three DGs with a gonadoblastoma component showed gains of 3p21 and loss of 5p, whereas none of the nine pure DGs had these changes, suggesting that they might be characteristic either of gonadoblastoma or of DG developing from a gonadoblastoma. Gain of 12p and gain from 1q were seen in three of four ESTs, whereas gains from 3p, 11q, and Xp and loss from 18q were each found in two tumors. Five of the ITs revealed changes (range, 1-4 changes/tumor), with gains from 1p, 16p, 19, and 22q each being found in two tumors. We conclude that ovarian DGs and ESTs seem to develop via the same genetic pathways that are already known for testicular germ cell tumors. On the other hand, ITs do not exhibit gain of 12p and also typically show fewer changes than other malignant OGCTs, indicating that they arise via different pathogenetic mechanisms.