bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of 1,320 nm Nd:YAG laser for wrinkle reduction and the treatment of atrophic acne scarring in Asians
Authors: Chan Henry H.L. , Lam Lai‐kun , Wong David S.Y. , Kono Taro , Trendell‐Smith Nigel 
Published: February 2004

AbstractBackground and objectivesThe role of 1,320 Nd:YAG in non‐ablative skin rejuvenation in Asians is has not been established. Furthermore, no study has investigated the effectiveness of 1,320 Nd:YAG laser in the treatment of atrophic scarring in Asians. The objective of our study was to investigate the effectiveness of 1,320 Nd:YAG laser in wrinkle reduction and the treatment of atrophic acne scarring in Asians.Study Design/Materials and MethodsTwenty‐seven female patients were included in the study: seven were treated for acne scarring and the others for wrinkle reduction. A 1,320 nm Nd:YAG laser (Cooltouch II, Roseville, CA) was used to treat both the cheeks and forehead for the patients with wrinkles, and both cheeks only for patients with atrophic acne scarring. All patients received treatment in the post‐auricular areas. A spot size of 10 mm was used, and three passes were performed (two pre‐cooling and one post‐cooling). Patients were treated monthly for 6 months. All patients were subjectively assessed before and after their last treatment sessions using a structured questionnaire, and objectively assessed by the use of clinical photographs for by independent observers. A cutometer was used to assess viscoelasticity, and biopsies were taken at the post‐auricular site for assessment by a pathologist.ResultsThe overall degree of patients' satisfaction was rated as 4.9 (range 0–9.8) for wrinkle reduction and 4 (range 0–10) for acne scarring. In terms of objective assessment by independent observers, the degree of improvement was considered to be mild or no change in most cases. The independent pathologist who assessed the degree of improvement in terms of increased collagen production detected no change in 8 patients, mild improvement in 9, and moderate improvement in 10.There was also improvement in term of epidermal thickness in 13 cases. Assessment by viscoelasticity indicated a significant degree of improvement in most parameters in both groups of patients. Blistering occurred in five cases, all in the central facial areas, and post‐inflammatory hyperpigmentation occurred in three cases. All cases of PIH resolved after the use of 4% hydroquinoine. There was no scarring or hypopigmentation.ConclusionsThe 1,320 nm Nd:YAG laser is effective for wrinkle reduction and atrophic acne scar improvement, but to further enhance the clinical outcome a combination approach with another device such as IPL and a surgical technique such as subcision is necessary. Lasers Surg. Med. 34:98–103, 2004. © 2004 Wiley‐Liss, Inc.
Port wine stain treatment with a dual‐wavelength Nd:Yag laser and cryogen spray cooling: A pilot study
Authors: Ahčan Uroš , Zorman Peter , Recek Dejan , Ralca Simon , Majaron Boris 
Published: February 2004

AbstractBackground and ObjectivesWe report on a pilot study of port wine stain (PWS) treatment with a prototype Nd:YAG/KTP laser system, emitting simultaneously at 1,064 and 532 nm, and equipped with a cryogen spray cooling (CSC) device.Study Design/Patients and MethodsOn 10 patients (4–36 years old, mean: 16.2 years) with skin types II‐III, therapeutic efficacy of the dual‐wavelength laser (KTP+) was compared with a standard KTP laser (532 nm only) at the same pulse duration (25 millisecond), spot diameter (3 mm), and CSC parameters. The fluences were selected in order to obtain the same immediate response with both laser systems. Blanching of each test segment was assessed 8 weeks post treatment by an independent evaluator and by the subjects, and graded on a 1–4 scale.ResultsSignificant blanching of PWS was noted 8 weeks after a single therapeutic session with the KTP+ laser (mean: 532 nm radiant exposure: 8.2 J/cm2), very similar to that observed with KTP at 12.4 J/cm2. The evaluator noticed a slight brownish coloration in areas treated with the KTP+ laser. Isolated beam‐sized atrophic scars were present in two patients where KTP+ (9 and 10 J/cm2) and KTP (14 J/cm2) lasers were used.ConclusionsThe addition of 1,064 nm radiation allowed a significant reduction of 532 nm radiant exposure with no loss of efficacy in PWS treatment. Lasers Surg. Med. 34:164–167, 2004. © 2004 Wiley‐Liss, Inc.
Treatment of alopecia areata with the 308‐nm xenon chloride excimer laser: Case report of two successful treatments with the excimer laser
Authors: Gundogan Cuneyt , Greve Bärbel , Raulin Christian 
Published: February 2004

AbstractBackground and ObjectivesAlopecia areata is a common disease of unknown etiology; it causes significant cosmetic and psycho‐social distress for most of the people it affects. We report on an innovative form of treatment in two patients with typical alopecia areata on the capillitium.Study Design/Patients and MethodsWe successfully treated two patients whose alopecia areata had worsened progressively for 3 and 14 weeks. The treatment involved the use of a 308 nm xenon chloride excimer laser (dosage 300–2,300 mJ/cm2 per session).ResultsAfter 11 and 12 sessions within a 9‐week and 11‐week period, the entire affected focus showed homogenous and thick regrowth. No relapse was observed during the follow‐up period of 5 and 18 months.ConclusionsThe use of the excimer laser is an effective, elegant, and safe means of treatment and has good tolerability. Analogous to topical treatment of alopecia areata, the immunosuppressive mechanism of the excimer laser can be interpreted as an induction of T‐cell apoptosis. This new means of treatment has yet to be discussed in medical literature. Further studies with greater numbers are needed to assess its potential more precisely and evaluate the excimer laser in treating alopecia areata. Lasers Surg. Med. 34:86–90, 2004. © 2004 Wiley‐Liss, Inc.
Increase of dermal blood volume fraction reduces the threshold for laser‐induced purpura: Implications for port wine stain laser treatment
Authors: Svaasand Lars O. , Aguilar Guillermo , Viator John A. , Randeberg Lise L. , Kimel Sol , Nelson J. Stuart 
Published: February 2004

AbstractBackground and ObjectivesThe average success rate in achieving total blanching of port wine stain (PWS) lesions treated with laser‐induced selective photothermolysis is below 25%, even after multiple treatments. This is because smaller diameter (5–20 μm) PWS blood vessels are difficult to destroy with selective photothermolysis since the volumetric heat generated by absorption of laser light is insufficient to adequately heat the entire vessel wall. The aim of this study was to investigate a potential technique for more efficient photocoagulation of small diameter PWS blood vessels in PWS that respond poorly to selective photothermolysis.Study Design/Materials and MethodsThe blood volume fraction (BVF) in the upper dermis of the forearm of human volunteers was increased by placing an inflated blood pressure cuff on the upper arm. Applied pressures were in the range of 80–100 mm Hg for up to 5 minutes. The increased BVF was determined by matching reflectance spectra measured with that computed using a diffusion model. The impact of increased BVF on purpura formation induced by a 0.45 milliseconds pulsed dye laser (PDL) at 585 nm wavelength was investigated in normal and in PWS skin.ResultsIn the presence of a 100 mm Hg pressure cuff, the BVF, as determined from the diffusion model, increased by a factor of 3 in the forearm and by 6 in the hand. Increasing BVF by a factor of 3 corresponds to an increase in blood vessel diameters by a factor of √3 ≈ 1.7. BVF increased at 1–3 minutes after application of the pressure cuff, remained constant at 3–5 minutes, and returned to baseline values at 3 minutes after removal of the pressure cuff. Approximately 40% less radiant exposure was needed to induce the same amount of purpura after PDL irradiation when the blood pressure cuff was used. Applying an 80 mm Hg pressure cuff reduced the required radiant exposure for purpura formation by 30%. Heating of blood vessels was calculated as a function of vessel diameter and of radiant exposure (at 585 nm and at 0.5 and 1.5 milliseconds pulse duration).ConclusionsEnlarging the vessel lumen, for example, by obstructing venous return, can significantly reduce the “small‐vessel‐limitation” in PDL treatment of PWS. Dilation of PWS blood vessels enables a more efficient destruction of smaller vessels without increasing the probability of epidermal damage. Lasers Surg. Med. 34:182–188, 2004. © 2004 Wiley‐Liss, Inc.
Effect of skin indentation on heat transfer during cryogen spray cooling
Authors: Basinger Brooke , Aguilar Guillermo , Nelson J. Stuart 
Published: February 2004

AbstractBackground and ObjectivesCryogen spray cooling (CSC) is used to pre‐cool the epidermis during dermatological laser procedures such as treatment of port wine stain (PWS) birthmarks, hair removal, and non‐ablative photorejuvenation. Thus far, heat transfer studies related to CSC optimization have assumed a flat surface but clinical observation suggests that human skin indents due to the force of an impinging cryogen spray.Study Design/Materials and MethodsHigh‐speed videos of cryogen spray impingement on in vivo human skin were taken and the resulting indentations characterized as a function of both nozzle‐to‐skin distance and anatomic location. Detectors with pre‐formed indentations were constructed and heat flux measurements were performed at two nozzle‐to‐surface distances.ResultsIndentation causes cryogen accumulation that reduces the efficiency of heat transfer when compared to spray impingement on a flat surface. Large indentations, however, encourage convective flow within the cryogen pool that mitigates many of the negative effects of liquid layer thickening and improves the heat flux.ConclusionsFlat surfaces produce the most efficient heat transfer, but once indentation exists (as it does in all clinically relevant cases), larger indentations produce a higher maximum heat flux. This suggests that higher momentum sprays (which produce larger skin indentations for identical spurts) than those in current clinical use may improve CSC efficiency. Lasers Surg. Med. 34:155–163, 2004. © 2004 Wiley‐Liss, Inc.
Polymeric Controlled Release Formulations of Niclosamide for Control of Biomphalaria Alexandrina, the Vector Snail of Schistosomiasis
Authors: Kenawy El‐Refaie , Rizk El‐Sayed 
Published: February 2004

AbstractSummary: Schistosomiasis is one of the most important public health problems in many developing countries. The present study was conducted to investigate the effect of the polymeric niclosamide formulations against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt. Three new polymeric formulations were prepared for the molluscicide niclosamide. The formulations were prepared either by the chemical modifications of poly(glycidyl methacrylate) or by physical entrapment of the niclosamide in calcium alginate beads. The release of the niclosamide from the polymeric formulations was investigated. The activity of the prepared formulations against Biomphalaria alexandrina was investigated. The results obtained revealed higher potency for polymerized niclosamide B3 than B1; the lowest potency was revealed for B2. After an exposure period of 24 hours, LC50 values were 0.073, 0.098 and 1.09 ppm for B3, B1 and B2, respectively. In addition, the molluscicidal potency of the test polymeric niclosamide was age‐dependent, where old snails were more tolerant to the test solutions than young and newly hatched snails. The results also indicated that the molluscicidal activity of B3 was extended for 21 days and 17 days for B1, compared with 5 days for free niclosamide. However, the molluscicidal potency of the polymerized niclosamide was increased after boiling for one hour, and was increased with increasing the pH of the medium to pH 9. In addition, their potency was increased with decreasing the water hardness concentrations (CaCO3).Molluscicidal activity of free niclosamide and its polymeric formulations vs. exposure time.imageMolluscicidal activity of free niclosamide and its polymeric formulations vs. exposure time.
Biomimetic Polymer/Apatite Composite Scaffolds for Mineralized Tissue Engineering
Authors: Zhang Ruiyun , Ma Peter X. 
Published: February 2004

AbstractSummary: The material surface must be considered in the design of scaffolds for bone tissue engineering so that it supports bone cells adhesion, proliferation and differentiation. A biomimetic approach has been developed as a 3D surface modification technique to grow partially carbonated hydroxyapatite (the bonelike mineral) in prefabricated, porous, polymer scaffolds using a simulated body fluid in our lab. For the rational design of scaffolding materials and optimization of the biomimetic process, this work focused on various materials and processing parameters in relation to apatite formation on 3D polymer scaffolds. The apatite nucleation and growth in the internal pores of poly(L‐lactide) and poly(D,L‐lactide) scaffolds were significantly faster than in those of poly(lactide‐co‐glycolide) scaffolds in simulated body fluids. The apatite distribution was significantly more uniform in the poly(L‐lactide) scaffolds than in the poly(lactide‐co‐glycolide) scaffolds. After incubation in a simulated body fluid for 30 d, the mass of poly(L‐lactide) scaffolds increased approximately 40%, whereas the mass of the poly(lactide‐co‐glycolide) scaffolds increased by about 15% (see Figure). A higher ionic concentration and higher pH value of the simulated body fluid enhanced apatite formation. The effects of surface functional groups on apatite nucleation and growth were found to be more complex in 3D scaffolds than on 2D films. Surprisingly enough, it was found that carboxyl groups significantly reduced the apatite formation, especially on the internal pore surfaces of 3D scaffolds. These findings are critically important in the rational selection of materials and surface design of 3D scaffolds for mineralized tissue engineering and may contribute to the understanding of biomineralization as well.SEM micrograph of a poly(L‐lactide) scaffold.imageSEM micrograph of a poly(L‐lactide) scaffold.
Direct Visualization of Straw Cell Walls by AFM
Authors: Yan Lifeng , Li Wan , Yang Jinlong , Zhu Qingshi 
Published: February 2004

AbstractSummary: The structural relationship of cellulose, hemicellulose, and lignin in plant cell walls is still a mystery needing to be explored. By using atomic force microscopy (AFM) the surface of straw at different layers was directly observed, and the structural characteristics were analyzed by topographic analysis and FT‐IR spectra. It was found that a compact layer of wax covered the outside of the straw, which protects the straw from insects and microorganisms. At the boundary of the primary and second wall there appears a network structure of cellulose and hemicellulose, with some lignin localised on the surface of the network. It is consistent with the model of a cell wall suggested by Vincent. Inside the second cell wall, there is a layer mainly composed of a cellulose crystalline region. High‐resolution AFM observation reveals that the crystalline structure consists of both triclinic and monoclinic unit cells.An AFM phase image showing the structural relation between cellulose microfibrils, hemicellulose, and lignin in the straw cell wall.imageAn AFM phase image showing the structural relation between cellulose microfibrils, hemicellulose, and lignin in the straw cell wall.
Preparation and Characterization of Novel Physically Cross‐linked Hydrogels Composed of Poly(vinyl alcohol) and Amine‐terminated Polyamidoamine Dendrimer
Authors: Wu Xu‐Ye , Huang Shi‐Wen , Zhang Jian‐Tao , Zhuo Ren‐Xi 
Published: February 2004

AbstractSummary: Poly(vinyl alcohol) (PVA) and polyamidoamine (PAMAM) dendrimers are water‐soluble, biocompatible and biodegradable polymers, which have been widely applied in biomedical fields. In this paper, novel physically cross‐linked hydrogels composed of PVA and amine‐terminated PAMAM dendrimer G6‐NH2 were prepared by cyclic freezing/thawing treatment of aqueous solutions containing PVA and G6‐NH2. The FT‐IR analysis and elemental analysis indicated that PAMAM dendrimer G6‐NH2 was successfully introduced into the formed hydrogels, possibly via hydrogen bonds among hydroxyl groups, amide groups and amino groups in PVA and PAMAM dendrimer in the process of freezing‐thawing cycle. Compared with physically cross‐linked PVA hydrogel, PVA/G6‐NH2 hydrogels show higher swelling ratios and faster re‐swelling rate due to the higher hydrophilicity of PAMAM dendrimer G6‐NH2. Higher contents of G6‐NH2 in PVA/G6‐NH2 hydrogels resulted in higher swelling ratios and faster re‐swelling rates. With increasing freezing/thawing cyclic times, the swelling ratios and re‐swelling rates of PVA/G6‐NH2 hydrogels decreased, which is similar to that of physically cross‐linked PVA hydrogel. Combining the special host property of polyamidoamine dendrimer, these novel physically cross‐linked hydrogels are expected to have potential use in drug delivery, including improving drug‐loading amounts in hydrogels and prolonging drug release time.Swelling ratios of physically cross‐linked PVA/G6‐NH2‐50 hydrogels prepared by three, six, nine freezing/thawing cycles. The swelling equilibrium experiments were carried out in distilled water at 25 °C.imageSwelling ratios of physically cross‐linked PVA/G6‐NH2‐50 hydrogels prepared by three, six, nine freezing/thawing cycles. The swelling equilibrium experiments were carried out in distilled water at 25 °C.
Cover Picture: Macromol. Biosci. 2/2004
Authors: Yavuz Handan , Denizli Adil 
Published: February 2004

Cover: Representative SEM micrographs of polyamide hollow‐fibers; (a) inner surface; (b) outer surface.Further details can be found in the Full Paper by H. Yavuz and A. Denizli* on page 84.
UV Laser‐Induced Gas‐Phase Copolymerization of Carbon Disulfide and Ethene
Authors: Tomovska Radmila , Urbanová Markéta , Fajgar Radek , Bastl Zdeněk , Šubrt Jan , Pola Josef 
Published: February 2004

AbstractSummary: The laser irradiation at 193 nm of a gaseous mixture of carbon disulfide and ethene induces the copolymerization of both compounds and affords the chemical vapour deposition of a C/S/H polymer, the composition of which indicates the reaction between two to three CS2 molecules and one C2H4 molecule. Polymer structure is interpreted on the basis of X‐ray photoelectron and FT‐IR spectra as consisting of >CS, >CC<, CH2CH2, (CC)SnC4 − n, C(CS)S, S(CS)S, and CSSC configurations. The gas‐phase copolymerization of carbon disulfide and ethene represents the first example of such a reaction between carbon disulfide and a common monomer.Scheme showing the expected reaction of excited CS2 molecules with other CS2 molecules to form dimers, which then react with another CS2 molecule or add to ethene.imageScheme showing the expected reaction of excited CS2 molecules with other CS2 molecules to form dimers, which then react with another CS2 molecule or add to ethene.
Differences between Ziegler–Natta and Single‐Site Linear Low‐Density Polyethylenes as Characterized by Inverse Gas Chromatography
Authors: Zhao Liyan , Choi Phillip 
Published: February 2004

AbstractSummary: Zero‐pressure weight‐fraction‐based Henry's constants $(H_{{\rm 12}}^0 )$ of two alkanes, two alkenes, and benzene in Ziegler–Natta (ZN) and single‐site (ss) linear low‐density polyethylenes (LLDPE) with different average branch contents, molecular‐weight averages ($\overline M _{\rm n}$ and $\overline M _{\rm w}$), and polydispersity indices (PDI) were measured in the temperature range of 170 to 230 °C using the technique of inverse gas chromatography. For both types of LLDPEs, the measured $H_{{\rm 12}}^0$ was insensitive to molecular weight and PDI. However, the branch content dependence differed significantly. In particular, ZN‐LLDPE exhibited a strong branch content dependence on $H_{{\rm 12}}^0$ while ss‐LLDPE did not. In fact, depending on the temperature and solvent used, $H_{{\rm 12}}^0$ of ZN‐LLDPE could drop as much as 21% with an increase in an average branch content from 13 to 35 branches per 1 000 backbone carbons, while the differences of $H_{{\rm 12}}^0$ between ss‐LLDPEs with comparable differences in branch content were well within experimental uncertainties (5%). This observation is also supported by the fact that comparable ZN‐ and ss‐LLDPEs exhibited larger differences in $H_{{\rm 12}}^0$ at higher average branch contents. The above findings strongly suggested that the liquid morphologies of ZN‐ and ss‐LLDPEs differ considerably. In particular, the local chain conformation and free volume characteristics (i.e., the size distribution and/or spatial distribution of the free volume holes) of them are rather different. Such differences become more pronounced at higher temperatures.The weight‐fraction‐based Henry's constant of n‐hexane and hex‐1‐ene in Ziegler–Natta (ZN) and single‐site (ss) linear low‐density polyethylenes (LLDPE) with different average branch contents.imageThe weight‐fraction‐based Henry's constant of n‐hexane and hex‐1‐ene in Ziegler–Natta (ZN) and single‐site (ss) linear low‐density polyethylenes (LLDPE) with different average branch contents.
Transcrystalline Morphology of an in situ Microfibrillar Poly(ethylene terephthalate)/Poly(propylene) Blend Fabricated through a Slit Extrusion Hot Stretching‐Quenching Process
Authors: Li Zhong‐Ming , Li Liang‐Bin , Shen Kai‐Zhi , Yang Wei , Huang Rui , Yang Ming‐Bo 
Published: February 2004

AbstractSummary: Isotactic poly(propylene) (iPP) transcrystallites are obtained in in situ microfibrillar polyethylene terephthalate (PET)/iPP blends during a slit extrusion‐hot stretching‐quenching process. Based on morphological information from X‐ray scattering and microscopy, three nucleation origins are proposed in microfibrillar reinforced blends under an elongational flow field: (a) the classical row nuclei model; (b) fiber nuclei; (c) nuclei induced by fiber assistant alignment. The last model provides a natural explanation for the case that transcrystallites only occur in some microfiber reinforced blends under flow rather than without the external field.AFM image for the transcrystalline layer of the microfibrillar blend.imageAFM image for the transcrystalline layer of the microfibrillar blend.
Soluble Polyamides and Polyimides Functionalized with Benzo‐15‐Crown‐5‐Pendant Groups
Authors: Maya Eva M. , Lozano Angel E. , de la Campa Jose G. , de Abajo Javier 
Published: February 2004

AbstractSummary: A new diamine monomer containing a crown ether was made to react with commercial diacid chlorides and dianhydrides to yield new aromatic polyamides and polyimides. The crown ether moiety was introduced as a pendant group so that the polymers showed enhanced solubility in organic solvents, good thermal properties (high transition temperatures and high thermal stability), and good film‐forming ability.The new aromatic polyamides and polyimides bearing a benzo‐15‐crown‐5‐pendant group synthesized here.imageThe new aromatic polyamides and polyimides bearing a benzo‐15‐crown‐5‐pendant group synthesized here.
Living Ring‐Opening Metathesis Polymerization of Norbornenes Containing Acetyl‐Protected Carbohydrates Using Well‐Defined Molybdenum and Ruthenium Initiators
Authors: Nomura Kotohiro , Sakai Ichiro , Imanishi Yukio , Fujiki Michiya , Miyamoto Yoshitaka 
Published: February 2004

AbstractSummary: Homopolymers and diblock copolymers that contain maltose or glucose residues have been prepared by ring‐opening metathesis polymerization of norbornene derivatives using a molybdenum–alkylidene initiator, Mo(CHCMe2Ph)(N‐2,6‐iPr2C6H3)(OtBu)2 (A). These polymerizations took place not only in a living fashion ($\overline M _{\rm w} /\overline M _{\rm n}$ = < 1.2) but also with almost quantitative initiation. Two types of ruthenium initiators, (Cy3P)2RuCl2(CHPh) (B) and (IMesH2)(Cy3P)RuCl2(CHPh) (C), have also been used to compare initiator performance under the same conditions.Structures for the polymers studied here.imageStructures for the polymers studied here.