Low-temperature dissociation of CO2 molecules on vicinal Cu surfaces.

The reaction of carbon dioxide on the vicinal Cu surfaces at low temperatures was investigated by infrared reflection absorption spectroscopy, scanning tunneling microscopy, X-ray photoelectron spectroscopy, and quadrupole mass spectrometry. Dissociation of CO2 molecules into CO on the Cu(997) and Cu(977) surfaces was observed at temperatures between 80 K and 90 K, whereas it did not occur on Cu(111) under a similar condition. CO and physisorbed CO2 were the main adsorbates during the reaction. In contrast, the amount of atomic oxygen on the surface was small. The dissociation of CO2 was promoted by the small amount of oxygen produced by the CO2 dissociation on the Cu surfaces. This leads to the induction period in the CO2 reaction; the initial reaction rate on the clean Cu surfaces was low, and the coadsorbed oxygen enhanced the dissociation reactivity of CO2. Mass analysis of desorption species during the reaction revealed that the observed CO formation on the vicinal Cu surface is mainly caused by an oxygen-exchange reaction with residual CO in an ultra-high vacuum chamber.

The roles of step-site and zinc in surface chemistry of formic acid on clean and Zn-modified Cu(111) and Cu(997) surfaces studied by HR-XPS, TPD, and IRAS.

The adsorption, desorption, and decomposition of formic acid (HCOOH) on Cu(111), Cu(997), Zn-Cu(111), and Zn-Cu(997) were systematically studied by high-resolution x-ray photoelectron spectroscopy, temperature programmed desorption, and infrared reflection absorption spectroscopy. On the clean Cu(111) surface, 13% of formic acid molecules adsorbed at 83 K were dissociated to form bidentate formate species by heating at 300 K; however, on the Zn-Cu(111) surface, only 4% of adsorbed HCOOH molecules were dissociated into the bidentate formate species. On the contrary, 13% of adsorbed HCOOH molecules were already dissociated into monodentate formate species on Cu(997) even at 83 K and 17% of adsorbed formic acid molecules were transformed to bidentate formate species by heating at 300 K, indicating that the stepped Cu surface has higher reactivity for HCOOH dissociation at low temperature. On the Zn-Cu(997) surface, 20% of formic acid became bidentate formate species in contrast to the case with Zn-Cu(111). Thus, the Zn deposited Cu step surface shows special activity for adsorption and dissociation of formic acid. The desorption peak maxima of the formate decomposition products (CO2 and H2) on Zn-Cu(997) were shifted to higher temperatures than those on Cu(997). Zn on Cu surfaces plays an important role in the stabilization of formate species, which probably leads to the decrease in the activation barrier for hydrogenation on the Zn-Cu alloyed surface.

Formation of BN-covered silicene on ZrB2/Si(111) by adsorption of NO and thermal processes.

We have investigated the adsorption and thermal reaction processes of NO with silicene spontaneously formed on the ZrB2/Si(111) substrate using synchrotron radiation x-ray photoelectron spectroscopy (XPS) and density-functional theory calculations. NO is dissociatively adsorbed on the silicene surface at 300 K. An atomic nitrogen is bonded to three Si atoms most probably by a substitutional adsorption with a Si atom of silicene (N≡Si3). An atomic oxygen is inserted between two Si atoms of the silicene (Si-O-Si). With increasing NO exposure, the two-dimensional honeycomb silicene structure gets destroyed, judging from the decay of typical Si 2p spectra for silicene. After a large amount of NO exposure, the oxidation state of Si becomes Si4+ predominantly, and the intensity of the XPS peaks of the ZrB2 substrate decreases, indicating that complicated silicon oxinitride species have developed three-dimensionally. By heating above 900 K, the oxide species start to desorb from the surface, but nitrogen-bonded species still exist. After flashing at 1053 K, no oxygen species is observed on the surface; SiN species are temporally formed as a metastable species and BN species also start to develop. In addition, the silicene structure is restored on the ZrB2/Si(111) substrate. After prolonged heating at 1053 K, most of nitrogen atoms are bonded to B atoms to form a BN layer at the topmost surface. Thus, BN-covered silicene is formed on the ZrB2/Si(111) substrate by the adsorption of NO at 300 K and prolonged heating at 1053 K.

Intra-dimer row and inter-dimer row coupling of the vibrational modes of chemisorbed CO on Si(001)-c(4×2) observed by angle-dependent transmission infrared spectroscopy.

The vibrational modes of chemisorbed CO on a Si(001) surface are investigated by means of transmission Fourier-transform infrared absorption spectroscopy. We observed the three components corresponding to the stretching vibration of the terminal-site CO adsorbed on the down-dimer sites of a Si(001) surface. The symmetric stretching vibration and asymmetric stretching vibration are observed separately. This assignment is consistent with the polarization dependence of the incident light and with the vibrational modes obtained by performing theoretical calculations. We found that both the intradimer row and interdimer row coupling should be considered to explain the appearance of the three components.

An Ethynylene-Bridged Pentacene Dimer: Two-Step Synthesis and Charge-Transport Properties.

A rigid and planar ethynylene-bridged pentacene dimer (PenD) was synthesized from pentacenequinone in two steps, skipping the conventional stepwise approach. A brickwork motif in the single crystal shows two-dimensionally extended electronic interaction in the solid state. Highly crystalline dip-coated films exhibited average hole mobility of 0.24 cm2 V-1 s-1 , comparable to that of the single-crystal organic field-effect transistors. This discovery and understanding of the reaction for the facile synthesis of ethynylene-bridged π-conjugated systems enables to the synthesis of a wide range of organic semiconducting materials.

Strong Hydrogen Bonds at the Interface between Proton-Donating and -Accepting Self-Assembled Monolayers on Au(111).

Hydrogen-bonding heterogeneous bilayers on substrates have been studied as a base for new functions of molecular adlayers by means of atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRAS), and density functional theory (DFT) calculations. Here, we report the formation of the catechol-fused bis(methylthio)tetrathiafulvalene (H2Cat-BMT-TTF) adlayer hydrogen bonding with an imidazole-terminated alkanethiolate self-assembled monolayer (Im-SAM) on Au(111). The heterogeneous bilayer is realized by sequential two-step immersions in solutions for the individual Im-SAM and H2Cat-BMT-TTF adlayer formations. In the measurements by AFM, a grained H2Cat-BMT-TTF adlayer on Im-SAM is revealed. The coverage and the chemical states of H2Cat-BMT-TTF on Im-SAM are specified by XPS. On the vibrational spectrum measured by IRAS, the strong hydrogen bonds between H2Cat-BMT-TTF and Im-SAM are characterized by the remarkably red-shifted OH stretching mode at 3140 cm-1, which is much lower than that for hydrogen-bonding water (typically ∼3300 cm-1). The OH stretching mode frequency and the adsorption strength for the H2Cat-BMT-TTF molecule hydrogen bonding with imidazole groups are quantitatively examined on the basis of DFT calculations.

Enhancement of CO2 adsorption on oxygen-functionalized epitaxial graphene surface under near-ambient conditions.

The functionalization of graphene is important in practical applications of graphene, such as in catalysts. However, the experimental study of the interactions of adsorbed molecules with functionalized graphene is difficult under ambient conditions at which catalysts are operated. Here, the adsorption of CO2 on an oxygen-functionalized epitaxial graphene surface was studied under near-ambient conditions using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS). The oxygen-functionalization of graphene is achieved in situ by the photo-induced dissociation of CO2 with X-rays on graphene in a CO2 gas atmosphere. The oxygen species on the graphene surface is identified as the epoxy group by XPS binding energies and thermal stability. Under near-ambient conditions of 1.6 mbar CO2 gas pressure and 175 K sample temperature, CO2 molecules are not adsorbed on the pristine graphene, but are adsorbed on the oxygen-functionalized graphene surface. The increase in the adsorption energy of CO2 on the oxygen-functionalized graphene surface is supported by first-principles calculations with the van der Waals density functional (vdW-DF) method. The adsorption of CO2 on the oxygen-functionalized graphene surface is enhanced by both the electrostatic interactions between the CO2 and the epoxy group and the vdW interactions between the CO2 and graphene. The detailed understanding of the interaction between CO2 and the oxygen-functionalized graphene surface obtained in this study may assist in developing guidelines for designing novel graphene-based catalysts.

Approach to Half-Nose and Proboscis Lateralis.

Half-nose or heminasal aplasia is an extremely rare congenital malformation, which has a withering effect both on the patient and the family. Proboscis lateralis is a rare facial anomaly resulting in the incomplete development of one side of the nose, which was first defined in 1861 by Forster in his monograph. Proboscis lateralis, cleft nose, and nasal agenesis are rare anomalies; however, half-nose is also an extremely rare condition. In the formation of half-nose deformities, either a facial cleft or nasal dysplasia is the assumed theories of embryological origin. In the reconstruction of proboscis lateralis tissue, local flaps and forehead flaps can be used for a functional and esthetically acceptable structure. The expanded forehead flap has become commonly used in recent years. Estimating the cosmetic result of surgery is an extreme challenge because of the accompanying nasal growth of the transferred tissue and the nose. In this study, the authors report on the reconstruction of half-nose and proboscis lateralis deformity with clinical results.

Longitudinal Follow-up of Individuals With Cleft Lip Using Three-Dimensional Stereophotogrammetry.

The usefulness of three-dimensional (3D) stereophotogrammetry for treating cleft lip (CL) has been well documented. However, there are only a few reliable anthropometric analyses in infants with CL because at this age they cannot assume a resting facial position. Since 2014, we have used a handheld 3D imaging system in the operating room to obtain optimal images of infants with CL and palate under general anesthesia. Currently, 168 infants with a unilateral cleft, 50 infants with bilateral clefts, and 47 infants with an isolated cleft palate are being followed up in this way for a maximum of 30 months. Most patients ≥3 years of age are cooperative and allow staff to obtain 3D images without sedation. We plan to follow them until adulthood, obtaining 3D images at every intervention. Each year, >150 infants can be added to this ongoing longitudinal study. Using an archive of these digital images, various retrospective studies can be attempted in the future, which include comparisons of the long-term outcomes of various surgical techniques and interventions at different time intervals. This is the first 2-year preliminary report of a 20-year longitudinal study.

CO2 adsorption on the copper surfaces: van der Waals density functional and TPD studies.

We investigated the adsorption of CO2 on the flat, stepped, and kinked copper surfaces from density functional theory calculations as well as the temperature programmed desorption and X-ray photoelectron spectroscopy. Several exchange-correlation functionals have been considered to characterize CO2 adsorption on the copper surfaces. We used the van der Waals density functionals (vdW-DFs), i.e., the original vdW-DF (vdW-DF1), optB86b-vdW, and rev-vdW-DF2, as well as the Perdew-Burke-Ernzerhof (PBE) with dispersion correction (PBE-D2). We have found that vdW-DF1 and rev-vdW-DF2 functionals slightly underestimate the adsorption energy, while PBE-D2 and optB86b-vdW functionals give better agreement with the experimental estimation for CO2 on Cu(111). The calculated CO2 adsorption energies on the flat, stepped, and kinked Cu surfaces are 20-27 kJ/mol, which are compatible with the general notion of physisorbed species on solid surfaces. Our results provide a useful insight into appropriate vdW functionals for further investigation of related CO2 activation on Cu surfaces such as methanol synthesis and higher alcohol production.

Estimating Implant Volume and Mastectomy-Specimen Volume by Measuring Breast Volume With a 3-Dimensional Scanner.

OBJECTIVES: Conventional 2-stage expander-implant breast reconstruction is frequently performed. However, direct to implant reconstruction should be considered if indicated and if circumstances allow. One difficulty in breast reconstruction postmastectomy is selection of the appropriate implant size prior to surgery. The ability to estimate implant volume and mastectomy-specimen volume from the preoperative breast volume using a 3-dimensional (3D) scanner would greatly facilitate reconstruction. We investigated the relation between preoperative breast volume, mastectomy-specimen volume, and implant volume. MATERIALS AND METHODS: Forty-eight women who underwent 2-stage expander-implant reconstruction between April 2014 and September 2015 were included in this study. A 3D scanner (Kinect V1; Microsoft Corporation, Redmond, Wash) was used for measuring preoperative breast volume. We evaluated the relation of the measured preoperative breast volume, the mastectomy-specimen volume, and the implant volume using the Pearson correlation coefficient. RESULTS AND CONCLUSIONS: A strong correlation existed between preoperative breast volume, mastectomy-specimen volume, and implant volume. The following formulae were calculated:Mastectomy-specimen volume (mL) = 1.01 × preoperative breast volume (mL) + 9.91Implant volume (mL) = 0.90 × preoperative breast volume (mL) + 65.42Implant volume (mL) = 0.68 × mastectomy-specimen volume (mL) + 68.26This study shows that preoperative breast volume, as measured by a 3D Kinect scanner, can provide useful assistance in the preoperative choice of implant size.

Nasolabial Growth in Individuals With Unilateral Cleft Lip and Palate: A Preliminary Study of Longitudinal Observation Using Three-Dimensional Stereophotogrammetry.

There are limited numbers of studies comparing the preoperative and postoperative facial features of infants with unilateral cleft lip and palate (UCLP) using three-dimensional (3D) stereophotogrammetry. The authors attempted an anthropometric analysis of nasolabial asymmetry 1 year after primary lip repair using a handheld 3D imaging system. Five different nasolabial dimensions in 24 infants with UCLP were measured using 3D images captured during primary lip repair and again, 1 year after the repair. The nasal and upper-lip elements of the cleft side were significantly changed after primary lip repair, and nasolabial asymmetry was anthropometrically improved. This is a preliminary longitudinal observation of nasolabial growth in individuals with UCLP using 3D stereophotogrammetric technique. The authors would like to follow these children until adulthood, capturing 3D images at every intervention.

Observation of Fano line shapes in infrared vibrational spectra of CO2 adsorbed on Cu(997) and Cu(111).

Adsorption states of carbon dioxide on the Cu(997) and Cu(111) surfaces were investigated by infrared reflection absorption spectroscopy, temperature programmed desorption, and X-ray photoelectron spectroscopy. CO2 molecules are physisorbed on the Cu(997) surface at temperatures below 70 K; neither chemisorption nor dissociation of CO2 occurs on the Cu(997) surface at this low temperature. However, the vibrational spectra of adsorbed CO2 depend significantly on the substrate temperature and coverage. IR spectra of CO2 vibrational modes at 70 K show asymmetric Fano line shapes, while only normal absorption bands are observed when CO2 is adsorbed at 20 K. Fano line shapes are also observed for CO2 on Cu(111) at 85 K. The observation of Fano effect indicates the coupling between the electronic continuum states of the Cu surface and the internal vibrational modes of CO2 even in such physisorbed system.

A New Surgical Approach for Tessier No. 4 Facial Cleft Reconstruction: Lip-Rescue Flap.

Craniofacial clefts are rare, severe challenges for surgeons about which there is limited literature. Tessier Number 4 (No. 4) clefts are one of the most complex craniofacial anomalies and present difficulties in surgical treatment. The most-common deformities associated with Tessier No. 4 clefts are displacements of the lower eyelids, medial canthus, and ala and decreased distance between the lower eyelids and lips. In surgery to correct these deformities, the greatest challenges are the design and the placement of the landmarks and incisions. Because of its relative rarity and wide range of severity, no definitive operative methods have been accepted for Tessier No. 4 facial cleft. The present study presents a new lip-rescue flap technique as an alternative approach for reconstructing Tessier No. 4 facial clefts.

Quantitative analysis of desorption and decomposition kinetics of formic acid on Cu(111): The importance of hydrogen bonding between adsorbed species.

Quantitative analysis of desorption and decomposition kinetics of formic acid (HCOOH) on Cu(111) was performed by temperature programmed desorption (TPD), X-ray photoelectron spectroscopy, and time-resolved infrared reflection absorption spectroscopy. The activation energy for desorption is estimated to be 53-75 kJ/mol by the threshold TPD method as a function of coverage. Vibrational spectra of the first layer HCOOH at 155.3 K show that adsorbed molecules form a polymeric structure via the hydrogen bonding network. Adsorbed HCOOH molecules are dissociated gradually into monodentate formate species. The activation energy for the dissociation into monodentate formate species is estimated to be 65.0 kJ/mol at a submonolayer coverage (0.26 molecules/surface Cu atom). The hydrogen bonding between adsorbed HCOOH species plays an important role in the stabilization of HCOOH on Cu(111). The monodentate formate species are stabilized at higher coverages, because of the lack of vacant sites for the bidentate formation.

Experience of using cultured epithelial autografts for the extensive burn wounds in eight patients.

UNLABELLED: In Japan, the cultured epithelial autografts "JACE" was accepted as a health insurance adaptation from January 1, 2009. We examined the extensive burn wounds in 8 patients by using a combination of autograft and JACE. After debridement, we managed the wound bed preparation by using artificial dermis. The wound bed was covered with fine tissue 2 weeks after we implanted artificial dermis and trafermin was used every day. Meshed 6:1 split-thickness autografts were placed onto the recipient wound bed under the JACE. The epidermalization was nearly complete within 3 to 4 weeks. RESULTS: A total of 39 patients underwent medical treatment of burns. All patients burned more than 30% total body surface area (TBSA). We divided them into 2 groups. The control group consisted of 31 patient, 23 men and 8 women. They underwent operation not using JACE but only autograft. The average age of the patients was 59.61 (3.85) years. The TBSA burned in this control group was 58.94% (3.89%). Operation times were 2.16 (0.24) hours. The overall survival rate was 35.5%. The study group consisted of 8 patients, 5 men and 3 women. The average age of the patients was 56.38 (7.04) years. The TBSA burned in this study group was 51.63% (4.17%). Operation times were 4.25 (0.59) hours, and the overall survival rate in this study group was 87.5%. The average take rate of JACE was 80.0% (3.09%) 4 weeks postoperatively. CONCLUSIONS: JACE is one of the cultured epithelial autografts. Although we managed the wound bed preparation by using artificial dermis instead of cryopreserved cadaver allograft, we were able to recognize a good result from grafting JACE on meshed 6:1 split-thickness autografts. The study group observed a significant difference in operation times compared with the control group. However, this treatment contributed to reducing the area of the donor site.

Energy level alignment of cyclohexane on Rh(111) surfaces: the importance of interfacial dipole and final-state screening.

Adsorption states and electronic structure of cyclohexane on clean and hydrogen-saturated Rh(111) surfaces were investigated by scanning tunneling microscopy and photoelectron spectroscopy. Monolayer cyclohexane molecules form an ordered superstructure on the clean Rh(111) surface. The energy level alignment of adsorbed cyclohexane depends on each adsorption site; molecular orbitals of adsorbed cyclohexane on the atop site have lower binding energies than those on the other sites. In contrast, it becomes insensitive to adsorption sites on the hydrogen-saturated Rh(111) surface. By preadsorption of hydrogen, all cyclohexane molecular orbitals are uniformly shifted to lower binding energy compared to those on the clean Rh(111) surface. The observed energy level alignment of cyclohexane on the Rh(111) surfaces is determined by the vacuum level shift and the final-state screening effects.

Kinetic and geometric isotope effects originating from different adsorption potential energy surfaces: cyclohexane on Rh(111).

Novel isotope effects were observed in desorption kinetics and adsorption geometry of cyclohexane on Rh(111) by the use of infrared reflection absorption spectroscopy, temperature programmed desorption, photoelectron spectroscopy, and spot-profile-analysis low energy electron diffraction. The desorption energy of deuterated cyclohexane (C(6)D(12)) is lower than that of C(6)H(12). In addition, the work function change by adsorbed C(6)D(12) is smaller than that by adsorbed C(6)H(12). These results indicate that C(6)D(12) has a shallower adsorption potential than C(6)H(12) (vertical geometric isotope effect). The lateral geometric isotope effect was also observed in the two-dimensional cyclohexane superstructures as a result of the different repulsive interaction between interfacial dipoles. The observed isotope effects should be ascribed to the quantum nature of hydrogen involved in the C-H···metal interaction.

Classification of recipient veins in microsurgical flap reconstructions of the lower extremities.

It is difficult to cure severe open fractures of the lower extremities due to the frequent occurrence of severe damage to soft tissues or blood vessels, as well as bone defects, and concomitant infection, such as osteomyelitis. If appropriate treatment is not performed, long-term complications, such as nonunion of the bone, intractable ulcers, or other disorders, may arise. Between 1993 and 2010, we reviewed the records of 27 patients, and 28 limbs were treated. A total of 31 free-tissue transfers were performed on these 28 limbs. In this study, we classified the degree of damage based on the operative appearance of the condition of the recipient vein. A state that was normal or near-normal was described as type I-normal. A vein that was buried under a scar, but was comparatively easy to detach and retained a moderate adventitia was classified as type II-moderate. A vein with close adhesion between the wall and the scar that was not easy to detach was described as type III-severe. We also examined the relationships between recipient vein type and each of the following: (1) concomitant injury, (2) bone reconstruction, (3) preoperative infection, (4) length of time from injury to reconstruction, (5) eventual reoperation, and (6) flap necrosis. The results showed that there was a statistically significant relationship between recipient vein type and each of the following: bone reconstruction, preoperative infection, eventual reoperation, and flap necrosis. The selection of recipient vein is a factor that greatly affects the outcome of reconstruction of open fractures of the lower extremities. It is important to preoperatively estimate the condition of recipient vein even though it is difficult to preoperatively assess the condition. In some cases, only recipient veins in poor condition can be found intraoperatively on the affected leg. Under such circumstances, a cross-leg flap or a vein graft should be performed without hesitation to use recipient veins in a better condition.

Two-dimensional superstructures and softened C-H stretching vibrations of cyclohexane on Rh(111): effects of preadsorbed hydrogen.

Adsorption structures and interaction of cyclohexane molecules on the clean and hydrogen-preadsorbed Rh(111) surfaces were investigated using scanning tunneling microscopy, spot-profile-analysis low-energy electron diffraction, temperature-programmed desorption, and infrared reflection absorption spectroscopy (IRAS). Various ordered structures of adsorbed cyclohexane were observed as a function of hydrogen and cyclohexane coverages. When the fractional coverage (θ(H)) of preadsorbed hydrogen was below 0.8, four different commensurate or higher-order commensurate superstructures were found as a function of θ(H); whereas more densely packed incommensurate overlayers became dominant at higher θ(H). IRAS measurements showed sharp softened C-H vibrational peaks at 20 K, which originate from the electronic interaction between adsorbed cyclohexane and the Rh surface. The multiple softened C-H stretching peaks in each phase are due to the variation in the adsorption distance from the substrate. At high hydrogen coverages they became attenuated in intensity and eventually diminished at θ(H) = 1. The gradual disappearance of the soft mode correlates well with the structural phase transition from commensurate structures to incommensurate structures with increasing hydrogen coverage. The superstructure of adsorbed cyclohexane is controlled by the delicate balance between adsorbate-adsorbate and adsorbate-substrate interactions which are affected by preadsorbed hydrogen.