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M Zukowski

Publications and source records attributed to M Zukowski.

At least 19 recordsLinked to original sources
PubMed2004

Coincidence bell inequality for three three-dimensional systems.

We construct a Bell inequality for coincidence probabilities on a three three-dimensional (qutrit) system. We show that this inequality is violated when each observer measures two noncommuting observables, defined by the so-called unbiased six-port beam splitter, on a maximally entangled state of two qutrits. The strength of the violation agrees with the numerical results presented by Kaszlikowski et al, quant-ph/0202019. It is proven that the inequality defines facets of the polytope of local variable models.

Journal Article↗
PubMed2002

No time loophole in Bell's theorem: the Hess-Philipp model is nonlocal.

Hess and Philipp recently claimed [(2001) Proc. Natl. Acad. Sci. USA 98, 14224-14227 and 14228-14233] that proofs of Bell's theorem have overlooked the possibility of time dependence in local hidden variables, hence the theorem has not been proven true. Moreover they present what is claimed to be a local realistic model of the EPR correlations. If this is true then Bell's theorem is not just unproven, but false. We refute both claims. First, we explain why time is not an issue in Bell's theorem, and second, we show that their hidden variables model violates Einstein separability. Hess and Philipp have overlooked the freedom of the experimenter to choose settings of a measurement apparatus at will: any setting could be in force during the same time period.

Journal Article↗
PubMed2002

Chemical synthesis of benzamide riboside.

The C-glycosidic nicotinamide riboside analogue (1) was prepared by reaction of ribonolactone 16 with the lithiated 2-oxazoline 13 followed by triethylsilane reduction of the hemiacetal 17 to the tetrahydrofurane 18. Cleavage of the oxazoline group in 20 to the acid 21, conversion of the acid chloride 22 to the amide 23, and hydrogenative debenzylation afforded the benzamide riboside 1. Phosphorylation of the acetonide 26 and acid-catalyzed cleavage of the resulting ketal yielded the pseudonucleotide 27.

Glycosides↗
PubMed2000

Violations of local realism by two entangled N-dimensional systems are stronger than for two qubits

Tests of local realism versus quantum mechanics based on Bell's inequality employ two entangled qubits. We investigate the general case of two entangled quantum systems defined in N-dimensional Hilbert spaces, or " quNits." Via a numerical linear optimization method we show that violations of local realism are stronger for two maximally entangled quNits ( 3</=N</=9) than for two qubits and that they increase with N. The two quNit measurements can be experimentally realized using entangled photons and unbiased multiport beam splitters.

Journal Article↗
PubMed2000

Feasible "Kochen-Specker" experiment with single particles

We present a simple experimental scheme which can be used to demonstrate an all-or-nothing-type contradiction between noncontextual hidden variables and quantum mechanics. The scheme, which is inspired by recent ideas by Cabello and Garcia-Alcaine, shows that even for a single particle, path and spin information cannot be predetermined in a noncontextual way.

Journal Article↗
PubMed2000

Experiments towards falsification of noncontextual hidden variable theories

We present two experiments testing the hypothesis of noncontextual hidden variables. The first one is based on observation of two-photon pseudo-Greenberger-Horne-Zeilinger correlations, with two of the originally three particles mimicked by the polarization degree of freedom and the spatial degree of freedom of a single photon. The second one, a single-photon experiment, utilizes the same trick to emulate two particle correlations, and is an "event ready" test of a Bell-like inequality, derived from the noncontextuality assumption. Modulo fair sampling, the data falsify noncontextual hidden variables.

Journal Article↗
PubMed1999

Laser therapy of spider leg veins: clinical evaluation of a new long pulsed alexandrite laser.

BACKGROUND: The response of spider leg veins to laser or intense pulsed light therapy has generally been characterized by varying degrees of success and frequently inconsistent clinical response rates. OBJECTIVE: The purpose of this study was to examine the effectiveness of the 755 nm long pulsed infrared alexandrite (LPA) laser for the treatment of leg telangiectasias. METHODS: This study was constructed in four phases. Phase I examined 28 patients with variable sized telangiectasias using 5 treatment parameters (15 J/cm2 x 1 pulse, 20 J/cm2 x 1 pulse, 20 J/cm2 x 2 pulses, 20 J/cm2 x 3 pulses, or 30 J/cm2 x 1 pulse). Each patient received 3 treatments at 4 week intervals with the LPA. Patient diaries were obtained to examine the effects of the treatments. Subjective grading was performed at each follow-up visit by the investigators. Blinded objective grading was performed at the conclusion of the study by trained observers. Phase II examined the effects of these treatment parameters on varying vessel diameters. Vessels were grouped into small (<0.4 mm), intermediate (0.4-1.0 mm), and large (1.0-3.0 mm) subsets. Phase III examined the effects of a combination of LPA treatment followed by 23.4% hypertonic saline sclerotherapy. Subjective and blinded objective grading was used to determine improvement after a single treatment with the LPA at 20 J/cm2, single pulsed with a pulse duration of 5 or 10 msec followed by treatment with 23.4% hypertonic saline injected 3, 7, 14, or 28 days after laser therapy. Phase IV involved biopsies after LPA treatment alone at time intervals of immediately posttreatment and 5 and 21 days posttreatment. RESULTS: These evaluations revealed that the optimal treatment parameters for LPA therapy alone appeared to be 20 J/cm2, double pulsed at a repetition rate of one Hz. After 3 treatments at 4 week intervals, subjective grading indicated a 63% reduction in leg telangiectasias. Medium diameter vessels responded best with small vessel diameters responding poorly, if at all. The addition of 23.4% hypertonic saline sclerotherapy performed 3 to 7 days after laser therapy (LPA at 20 J/cm2, single pulsed with a pulse duration of 5 msec) produced 87% reduction in leg telangiectasias. Biopsies after LPA treatment revealed vessel wall endothelial cell necrosis at 5 days with fibrosis occurring at 3 weeks. The optimal clinical "window" for sclerotherapy seems to coincide with the period of endothelial cell necrosis. CONCLUSION: LPA therapy is most effective for leg telangiectasias 0.4-3.0 mm in diameter. This LPA technique is significantly improved with the addition of sclerotherapy.

Adult↗
PubMed1999

Laser hair removal: a review and report on the use of the long-pulsed alexandrite laser for hair reduction of the upper lip, leg, back, and bikini region.

BACKGROUND: The mechanism and permanence of laser-assisted hair removal remains a formidable task in the medical community. OBJECTIVE: The purpose of this study was to determine the safety and long-term efficacy of the long-pulsed or normal mode alexandrite infrared laser for hair depilation. METHODS: Beginning in October 1996, a total of 31 anatomic sites on 22 patients ranging in age from 25 to 59 years (mean 42 years) were evaluated to assess hair removal. Treatment sites included 17 upper lips, 9 legs, 2 backs, and 3 bikini regions. Eligible patients were of Fitzpatrick skin types I-III. Patients were treated using the long-pulsed alexandrite infrared laser at 755 nm, single-pulse technique, 10 mm spot size, 10% overlap, pulse durations of 5, 10, and 20 msec, and a fluence of 20 J/cm2. Subjective patient improvement and objective, blinded graded improvement was assessed at 1, 2, 3, and 6 months. RESULTS: Objective blinded grading at 6 months revealed that hair reduction varied both with the pulse duration and anatomic location. Maximum reductions observed were 40%, 56%, 50%, and 15% for the lip, leg, back, and bikini areas, respectively. Upper lip hair reduction increased from 40% to 54% at 6 months when a second treatment was performed 8 weeks after the initial treatment. CONCLUSION: The long-pulsed alexandrite laser is safe and effective in reducing hair growth. Treatment efficacy varies with the anatomic location, pulse duration, and number of treatments. A single-pulse technique utilizing a 10 msec pulse duration at 20 J/cm2 produced the greatest hair reduction. No permanent adverse effects occurred on skin types I-III at the parameters tested.

Adult↗
PubMed1998

The gracilis free flap revisited: a review of 25 cases of transfer to traumatic extremity wounds.

Trauma to the extremities often results in a complex bony and soft-tissue injury requiring free flap reconstruction. Muscles from various body sites have been used in extremity reconstruction since the early 1970s. The gracilis muscle is usually not considered the first choice for free flap reconstruction of these defects. It is usually relegated to small defects or used to reanimate the face. Our purpose is to present our experience with the gracilis muscle as a first-choice flap in reconstruction of traumatic extremity defects. A retrospective review of all gracilis muscle free flap transfers for traumatic extremity wounds between 1988 and 1995 at the Naval Medical Center Portsmouth was performed. Twenty-five patients age 20 to 71 years (mean, 29.7 years) underwent 26 free flaps to the lower leg, ankle, foot, or forearm to cover traumatic wounds. Defects ranged in size from 3 x 3 cm (9 cm2) to 13 x 18 cm (234 cm2), with a mean of 75.5 cm2. There were no flap losses and all wounds healed. Nine patients experienced 11 complications, which consisted of minor wound separation (16%), wound infection (12%), partial or complete loss of split-thickness skin graft (8%), thrombosis of graft with successful revascularization (4%), and nonunion of an underlying fracture (4%). Our overall success rate for gracilis free flap reconstruction of traumatic wounds is 100%. The gracilis free muscle flap has become our first option for tissue coverage in traumatized extremities. It leaves minimal functional defect limited to the side of the primary injury and provides a good cosmetic result. It can cover large defects when the epimysium is cut, and allows an epidural block to be performed for sympathectomy effect and pain control in the affected extremity during the immediate postoperative period.

Adult↗
PubMed1998

Accelerated laser resurfacing wound healing using a triad of topical antioxidants.

BACKGROUND: The speed of wound healing and the duration of erythema are the primary complaints after laser skin resurfacing. Antioxidants have been shown to enhance the healing of wounds by reducing free radical damage. Reepithelialization is also enhanced by the moist environment produced by occlusive dressings. OBJECTIVE: This study was conducted to compare two occlusive agents: white petrolatum and "melting" petrolatum. Another arm of the study evaluated the use of melting petrolatum with and without a triad of topical antioxidants (TTA). RESULTS: Plain white petrolatum proved superior to melting petrolatum in time required for reepithelialization as well as in discomfort. Crusting and pain were decreased with white petrolatum but duration of erythema was equivalent. Wound healing was enhanced when TTA was added. Time for reepithelialization, duration of crusting and scabbing, pain, redness, and swelling were decreased when TTA was added to topical therapy. CONCLUSION: TTA compound enhances and hastens wound healing. White petrolatum as a base occlusive vehicle shortens reepithelialization compared with "melting" petrolatum.

Administration, Cutaneous↗
PubMed1998

Comparison of topical therapy for striae alba (20% glycolic acid/0.05% tretinoin versus 20% glycolic acid/10% L-ascorbic acid).

BACKGROUND: Topical treatment of striae rubra with 0.1% tretinoin and laser treatment of striae rubra and alba with the 585-nm pulsed dye laser are proven therapeutic options. However, little efficacy has been shown for treatment of striae alba topically, and the laser is currently not a suitable treatment option for darker ethnic skin types. OBJECTIVE: The purpose of this study was to demonstrate that selected commercial topical agents can improve the appearance of striae alba. METHODS: Ten patients of varying skin types (I-V) having straie distensae alba on the abdomen or thighs were selected to evaluate the effectiveness of two topical treatment regimens. Patients were placed on daily topical application of 20% glycolic acid (MD Forte) to the entire treatment area. In addition, the patients applied 10% L-ascorbic acid, 2% zinc sulfate, and 0.5% tyrosine to half to the treatment area and 0.05% tretinoin emollient cream (Renova) to the other half of the treatment area. The creams were applied on a daily basis for 12 weeks. Improvement was evaluated at 4 and 12 weeks in an objective unblinded fashion at the follow-up visits, a objective blinded fashion by visual grading at the conclusion of the study, and in an objective blinded fashion with profilometry. Additionally, histopathologic analysis was performed. RESULTS: Analysis of these data reveals: 1) both regimens can improve the appearance of stretch marks; 2) these topical therapy regimens are safe and effective in study patients with minimal irritation; 3) elastin content within the reticular and papillary dermis can increase with topical 20% glycolic acid combined with 0.05% tretinoin emollient cream therapy; 4) both regimens increased epidermal thickness and decreased papillary dermal thickness in treated stretch marks when compared with untreated stretch marks; 5) combined epidermal and papillary dermal thickness in stretch marks treated with either topical regimen approaches that of normal skin; and 6) profilometry can objectively measure differences in skin texture associated with striae treatments when compared to controls, however, it is not sensitive enough to justify comparison or quantitative improvements between similarly effective treatments.

Abdomen↗
PubMed1997

Activation of stress-activated protein kinases/c-Jun N-terminal protein kinases (SAPKs/JNKs) by a novel mitogen-activated protein kinase kinase.

Mitogen-activated protein kinase (MAPK) kinases (MKKs) are dual-specificity protein kinases that phosphorylate and activate MAPK. We have isolated a cDNA encoding a novel protein kinase that has significant homology to MKKs. The novel kinase MKK7 has a nucleotide sequence that encodes an open reading frame of 347 amino acids with 11 kinase subdomains. MKK7 is ubiquitously expressed in all adult and embryonic organs but displays high expression in epithelial tissues at later stages of fetal development. When transiently expressed in 293 cells, MKK7 specifically activated stress-activated protein kinases (SAPKs)/c-Jun N-terminal protein kinases (JNKs) but not extracellular-regulated kinase or p38 kinase. A kinase-negative mutant of MKK7 inhibits interleukin-1beta, lipopolysaccharide, and MEKK1-induced SAPK/JNK activation. Thus, MKK7 is a new member of the MAPK kinase family that functions upstream of SAPK/JNK in the SAPK/JNK signaling pathway.

Amino Acid Sequence↗
PubMed1997

Molecular cloning and characterization of a novel p38 mitogen-activated protein kinase.

The p38 mitogen-activated protein kinases (MAPK) are activated by cellular stresses and play an important role in regulating gene expression. We have isolated a cDNA encoding a novel protein kinase that has significant homology (57% amino acid identity) to human p38alpha/CSBP. The novel kinase, p38delta, has a nucleotide sequence encoding a protein of 365 amino acids with a putative TGY dual phosphorylation motif. Dot-blot analysis of p38delta mRNA in 50 human tissues revealed a distribution profile of p38delta that differs from p38alpha. p38delta is highly expressed in salivary gland, pituitary gland, and adrenal gland, whereas p38alpha is highly expressed in placenta, cerebellum, bone marrow, thyroid gland, peripheral leukocytes, liver, and spleen. Like p38alpha, p38delta is activated by cellular stress and proinflammatory cytokines. p38delta phosphorylates ATF-2 and PHAS-I, but not MAPK-activated protein kinase-2 and -3, known in vivo and in vitro substrates of p38alpha. We also observed that p38delta was strongly activated by MKK3 and MKK6, while p38alpha was preferentially activated by MKK6. Other experiments showed that a potent p38alpha kinase inhibitor AMG 2372 minimally inhibited the kinase activity of p38delta. Taken together, these data indicate that p38delta is a new member of the p38 MAPK family and that p38delta likely has functions distinct from that of p38alpha.

Amino Acid Sequence↗
PubMed1997

Activation of the c-Jun N-terminal kinase pathway by a novel protein kinase related to human germinal center kinase.

The c-Jun N-terminal kinase (JNK), or stress-activated protein kinase plays a crucial role in cellular responses stimulated by environmental stress and proinflammatory cytokines. However, the mechanisms that lead to the activation of the JNK pathway have not been elucidated. We have isolated a cDNA encoding a novel protein kinase that has significant sequence similarities to human germinal center kinase (GCK) and human hematopoietic progenitor kinase 1. The novel GCK-like kinase (GLK) has a nucleotide sequence that encodes an ORF of 885 amino acids with 11 kinase subdomains. Endogenous GLK could be activated by UV radiation and proinflammatory cytokine tumor necrosis factor alpha. When transiently expressed in 293 cells, GLK specifically activated the JNK, but not the p42/44(MAPK)/extracellular signal-regulated kinase or p38 kinase signaling pathways. Interestingly, deletion of amino acids 353-835 in the putative C-terminal regulatory region, or mutation of Lys-35 in the putative ATP-binding domain, markedly reduced the ability of GLK to activate JNK. This result indicates that both kinase activity and the C-terminal region of GLK are required for maximal activation of JNK. Furthermore, GLK-induced JNK activation could be inhibited by a dominant-negative mutant of mitogen-activated protein kinase kinase kinase 1 (MEKK1) or mitogen-activated protein kinase kinase 4/SAPK/ERK kinase 1 (SEK1), suggesting that GLK may function upstream of MEKK1 in the JNK signaling pathway.

Amino Acid Sequence↗