Reconfigurable infrared hyperbolic metasurfaces using phase change materials.

Metasurfaces control light propagation at the nanoscale for applications in both free-space and surface-confined geometries. However, dynamically changing the properties of metasurfaces can be a major challenge. Here we demonstrate a reconfigurable hyperbolic metasurface comprised of a heterostructure of isotopically enriched hexagonal boron nitride (hBN) in direct contact with the phase-change material (PCM) single-crystal vanadium dioxide (VO2). Metallic and dielectric domains in VO2 provide spatially localized changes in the local dielectric environment, enabling launching, reflection, and transmission of hyperbolic phonon polaritons (HPhPs) at the PCM domain boundaries, and tuning the wavelength of HPhPs propagating in hBN over these domains by a factor of 1.6. We show that this system supports in-plane HPhP refraction, thus providing a prototype for a class of planar refractive optics. This approach offers reconfigurable control of in-plane HPhP propagation and exemplifies a generalizable framework based on combining hyperbolic media and PCMs to design optical functionality.

Smoking cessation counseling by resident physicians in internal medicine, family practice, and pediatrics.

Residents in primary care specialties care for many patients who smoke cigarettes, but little is known about their smoking cessation counseling (SCC). We surveyed 309 residents (72 family practice, 171 internal medicine, and 66 pediatrics residents) in 13 programs to determine their practices, knowledge, attitudes, and training in SCC. More than 90% thought physicians are responsible for SCC, the majority routinely took smoking histories, and 80% attempted to motivate patients to quit smoking. However, 25% or fewer reported discussing obstacles to quitting, setting a quit date, prescribing nicotine gum, scheduling follow-up visits, or providing self-help materials. Family practice residents used more SCC techniques (1.8) than did internal medicine (0.8) and pediatrics (0.1) residents. Only 54% of residents reported recent SCC training and 13% reported formal SCC training. Recent training correlated with the number of counseling techniques used. Residents in primary care specialties report positive attitudes but inadequate practice and training in SCC.

Sexually transmitted diseases in sexually abused children.

Over a 4-year period, 409 cases of suspected sexual abuse of children were reviewed to study sexually transmitted disease (STD). Sexually transmitted disease was identified in 54 (13%) of the 409 children: 46 cases of gonorrhea, six cases of syphilis, four cases of trichomoniasis, and three cases of condyloma acuminata. Nine of the 46 children with cultures positive for gonorrhea did not have a history of discharge. Four of the six children with syphilis also had a gonococcal infection. One child with syphilis had condyloma. Only one child had clinical features of syphilis. Sexually transmitted disease was more likely to be transmitted by an extended family member or a nonfamily member than by a father/stepfather (P less than .001). Laboratory tests that identify sexually transmitted disease may aid in the diagnosis of sexual abuse.

Epidemiology of adult sexually transmitted disease agents in children being evaluated for sexual abuse.

This prospective study describes the epidemiology of adult sexually transmitted disease agents in 1538 children ages 1 to 12 years being evaluated for possible sexual abuse. Infections with these agents were related to the presence or absence of a history of sexual contact. Neisseria gonorrhoeae (GC) was found in 2.8% (41 of 1469); human papillomavirus presenting as condyloma acuminata, 1.8%; Chlamydia trachomatis, 1.2% (17 of 1473); Treponema pallidum (syphilis), 0.1% (1 of 1263); and herpes simplex virus, 0.1%. Overall a history of sexual contact was present in 83% of children with N. gonorrhoeae; condyloma acuminata, 43%; Chlamydia trachomatis, 94%; syphilis, 0%; and herpes simplex virus, 50%. Selected vaginal discharges were examined for Trichomonas vaginalis and bacterial vaginosis. In children comprehending questions regarding sexual contact (i.e. were "verbal"), 89% with N. gonorrhoeae, 100% with Chlamydia trachomatis and 63% with condyloma acuminata had a history of sexual contact, indicating that in "verbal" children any infection with N. gonorrhoeae or C. trachomatis was highly associated with sexual contact.

The effect of stannous fluoride on plaque scores.

A homogeneous group of 37 patients was chosen. The first six days involved brushing and rinsing with stannous fluoride compounds for the experimental group and placebo compounds for the control group. The next five days involved rinsing only. There was a significant difference in plaque scores during the period of rinsing only.

Black intraocular lens for leukocoria.

We describe a 33-year-old man with leukocoria and no visual potential who obtained an excellent cosmetic result after cataract extraction and implantation of an intraocular lens with an entirely black optic.

Surreptitious warfarin ingestion.

Munchausen by proxy has been reported involving children who have been given various drugs or toxins. In addition, there is a body of adult literature regarding covert anticoagulant ingestion. This is a case of an 11-month-old female who appears to combine features of both of these syndromes. This child presented with an acute left hemorrhagic otitis media. The physical examination was unremarkable except for the following: weight, fifth percentile; left external auditory canal filled with blood with the right external canal and tympanic membrane being normal; and several scattered 1 X 2 cm firm, movable, nontender, purple nodules on extremities, chest and forehead. The coagulation studies were consistent with Vitamin K deficiency secondary to anticoagulant ingestion. A serum warfarin study confirmed our suspicions. The mother was noted to have a dependent relationship with her child and characteristics of those involved in Munchausen by proxy: falsifying information and thwarting medical assessment. In addition, she displayed some of the characteristics found commonly in anticoagulant malingerers. She was depressed, with limited medical knowledge, and had access to warfarin. The mother was admitted for inpatient psychiatric care and the patient placed with an extended family member. This case report describes the use of an anticoagulant to induce illness in a child by a psychologically ill mother. This form of child abuse must be considered in the differential diagnoses of hemorrhagic disorders.

Vaginal introital diameter in the evaluation of sexual abuse.

Physical objective markers to aid in the diagnosis of sexual abuse are few. We therefore studied 242 females, ages 1 through 12 years, to determine if the vaginal introital diameter is useful in evaluating a child for sexual abuse. The children were divided into three groups: Group I, history of sexual contact and/or Neisseria gonorrhoeae; Group II, no history of sexual contact but at risk; and Group III, nonabused. A vaginal introital transverse diameter of greater than 4 mm was more prevalent among children in Group I (94%) than in Group II, (5%); or in Group III (0%) (chi 2, p less than .001). Eighty-eight percent of children who complained of penile-vaginal penetration had a vaginal introital diameter greater than 4 mm as compared to 18% of children with no penetration (chi 2, p less than .001). Forty-six percent of children who complained of fondling with penetration had a vaginal introital diameter of greater than 4 mm as compared to 14% in those without a history of penetration (chi 2, p less than .008). Fifty-eight percent of children with more than one encounter had a vaginal introital diameter greater than 4 mm as compared to 29% in those with one encounter (chi 2, p less than .006). In a logarithmic regression analysis, the greatest proportion of children with a vaginal introital diameter greater than 4 mm was observed in the penile-vaginal contact group (chi 2, p less than .00003). The test is not very sensitive but highly specific. The sensitivity drops precipitously at greater than 5 mm without losing the specificity. A vaginal introital diameter of greater than 4 mm is highly associated with sexual contact in children less than 13 years of age.

Gardnerella vaginalis infection and sexual contact in female children.

Gardnerella vaginalis (GV) infection has been reported as being acquired via sexual contact in adults and as an indicator of sexual contact in female children (DeJong, 1985). The purpose of this study was to determine if GV infection was more commonly found in 191 female children who gave a history of sexual contact and/or were infected with Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT) (Group 1), compared with 144 female children evaluated for possible sexual abuse and found to have no such history or infection with GC or CT (Group 2), or 31 female children (friends of the authors) without such a history or GC or CT infection (Group 3). Vaginal GV was found in 5.3% of Group 1, 4.9% of Group 2 and 6.4% of Group 3 (p > .05). Also, vaginal GV infection was not related to the type of sexual contact or race, but did increase with age in white female children. Because vaginal GV infection is not more commonly found in children with a history of sexual contact than those without such a history, the finding of GV in a vaginal culture in an individual case would not be a reliable marker of sexual contact. Routine culturing for GV is not recommended as part of a sexual abuse workup.

Ureaplasma urealyticum and large colony mycoplasma colonization in female children and its relationship to sexual contact, age, and race.

In order to determine if Ureaplasma urealyticum (Uu) or large colony mycoplasma (LCM) colonization was related to a history of sexual abuse, the type of sexual contact, an enlarged vaginal introitus transverse diameter (greater than 4 mm), age or race, 452 female children, ages 1-12 years, were evaluated by the Child Sexual Abuse Team at Wake Medical Center in Raleigh, NC. Thirty-six girls were deleted because of inadequate cultures. When controlled for race and age, Uu throat (T), vaginal (V), and rectal (R) colonization and LCM vaginal and rectal colonization were not related to any of the other variables listed above. The enlarged vaginal introital diameter was related to a history of sexual abuse (p less than .001). Uu and LCM vaginal colonization rates were increased in black girls as compared to white girls (p less than .05). Uu V, Uu R, LCM V, and LCM R colonization increased with age. In our study population, Uu and LCM colonization was not a useful marker of sexual contact.

Ankyloblepharon filiforme adnatum.

Two cases of a rare congenital eyelid abnormality, ankyloblepharon filiforme adnatum, are presented, and novel aspects of treatment, associations and classification are discussed.

Sexual contact in children with gonorrhea.

This study was performed to determine if gonorrheal infections in children aged 1 to 12 years were frequently associated with sexual contacts. In our study all 14 children who had gonorrhea and who were over 4 years of age and 35% (six) of the 17 children who had gonorrhea and who were between 1 and 4 years old were found to have had sexual contact with older males who were almost always in the extended family. Our study supports the concept that gonorrhea in children over 4 years old is almost always associated with sexual contact. In children between 1 and 4 years old, a history of sexual contact is more difficult to obtain but may be elicited in more than a third of the cases. Hospitalization of the children and identification of extended family members with gonorrhea, followed by additional interviews, were useful procedures in determining who had had sexual contact with the children.

Economy of Carbon and Nitrogen in Nodulated and Nonnodulated (NO(3)-grown) Cowpea [Vigna unguiculata (L.) Walp.].

The response of non-nodulated cowpea (Vigna unguiculata (L.) Walp. cv Caloona) to a wide range of NO(3) levels in the rooting medium was studied 40 days after sowing by in vitro assays of plant organs for NO(3) reductase (EC 1.6.6.1) and analyses of root bleeding (xylem) sap for nitrogenous solutes. Plants fed 1, 5, 10, 20, and 40 millimolar NO(3) showed, respectively, 64, 92, 94, and 91% of their total reductase activity in shoots and 34, 30, 66, 62, and 58% of the total N of their xylem sap as NO(3). These data, and the absence in the plants of significant pools of stored NO(3), indicated that shoots were major organs of NO(3) assimilation, especially at levels of NO(3) (10 to 40 millimolar) that maintained plant growth at near maximum rates. Partitioning and utilization of C and N were studied in nodulated, minus NO(3) plants and non-nodulated plants fed 10 or 20 millimolar NO(3), the levels of NO(3) which gave rates of growth and N assimilation closest to those of the symbiotic plants. The conversion of the C of net photosynthate to dry matter was similar in nodulated plants (67%) and NO(3)-grown plants (64%), but greater proportions of photosynthate were translocated to below ground parts of nodulated plants (37%) than of NO(3)-fed plants (23 to 26%). Greater photosynthate consumption by nodulated roots was associated with proportionately greater root growth and respiration and 2-fold greater export of C in xylem than in the NO(3)-fed plants. Theoretical considerations suggest that the elevated CO(2) output of nodulated roots was due not only to CO(2) loss associated with nodule function, but also to a much greater nonassimilatory component of respiration in the supporting root of the nodulated plant compared to roots of the NO(3)-fed plants. Data are compared with previously published information from other legumes.

Childhood vaginal infections: association of Chlamydia trachomatis with sexual contact.

To determine whether infections with Chlamydia trachomatis in children were significantly associated with previous sexual contact, we studied 124 female children ages 1 through 12 years with previous sexual contact and 90 female children without previous sexual contact. Vaginal, pharyngeal and rectal cultures for C. trachomatis were performed. Ten children with previous sexual contact and none without previous sexual contact had vaginal infections (P = 0.022, chi square test with 2 degrees of freedom). Rectal infections (three) and pharyngeal infections (two) were too few to relate statistically to sexual contact. We recommend that all female children being evaluated for sexual abuse be cultured for C. trachomatis, inasmuch as vaginal C. trachomatis is an excellent marker of sexual contact.

Improvements in measures of vision and self-reported visual function after cataract extraction in patients with late-stage age-related maculopathy.

PURPOSE: A recent study indicated that patients with cataracts and early age-related maculopathy may benefit from cataract extraction. To ascertain whether cataract extraction in the presence of concurrent advanced age-related maculopathy was also associated with a clear benefit, we studied visual function and self-reported visual functioning in a cohort of 12 patients pre- and post-phakoemulsification. METHODS. All 12 patients had a diagnosis of advanced age-related maculopathy in the eye scheduled for cataract surgery. Preoperative assessment included refraction and recording of best corrected distance and near acuity and contrast sensitivity in both eyes. The Daily Living Tasks Dependent on Vision questionnaire was administered. After phakoemulsification and intraocular lens implantation, all patients were reviewed and assessed. RESULTS: After surgery, improvement in acuity was recorded in nine operated eyes, whereas acuity remained unchanged in three eyes. Improvement in contrast sensitivity in the operated eye occurred in 10 patients, but in two patients contrast was reduced postoperatively. In terms of self-reported visual functioning, improvement in the ability to undertake many daily living tasks dependent on vision was recorded after cataract surgery. CONCLUSIONS: Significant improvements in specific areas of self-reported visual functioning and measures of vision were recorded after cataract surgery. During the follow-up period, none of the operated eyes suffered a fall in visual acuity. There was also no evidence of worsening of the pre-existing macular lesion as judged by clinical examination and fundus photography.

Nitrogen Nutrition and Xylem Transport of Nitrogen in Ureide-producing Grain Legumes.

Xylem sap composition was examined in nodulated and nonnodulated cowpea (Vigna unguiculata [L.] Walp.) plants receiving a range of levels of NO(3) and in eight other ureide-forming legumes utilizing NO(3) or N(2) as sole source of nitrogen. A (15)N dilution technique determined the proportions of plant nitrogen derived from N(2) in the nodulated cowpeas fed NO(3). Xylem sap composition of NO(3)-fed, nodulated cowpea varied predictably with the relative extents to which N(2) and NO(3) were being utilized. The ratios of asparagine to glutamine (N/N) and of NO(3) to ureide (N/N) in xylem sap increased with increasing dependence on NO(3) whereas per cent of xylem nitrogen as ureide and the ratio of ureide plus glutamine to asparagine plus NO(3) (N/N) in xylem sap increased with increasing dependence on N(2) fixation. The amounts of NO(3) and ureides stored in leaflets, stems plus petioles, and roots of cowpea varied in a complex manner with level of NO(3) and the presence or absence of N(2) fixation. All species showed higher proportions of organic nitrogen as ureide and several-fold lower ratios of asparagine to glutamine in their xylem sap when relying on N(2) than when utilizing NO(3). In nodulated (minus nitrate) cowpea and mung bean (Vigna radiata [L.] Wilczek) the percentage of xylem nitrogen as ureide remained constant during growth but the ratio of asparagine to glutamine varied considerably. The biochemical significance of the above differences in xylem sap composition was discussed.

Expression of human terminal deoxynucleotidyl transferase in Escherichia coli.

A cloned DNA fragment related to pT17 containing a partial cDNA sequence of human terminal deoxynucleotidyl transferase was used as a probe to screen for the full length cDNA sequence of the enzyme in a lambda gt11 library constructed from human lymphoblastoid KM-3 cDNA. A recombinant containing a 2068-base pair insert was isolated and recloned into the EcoRI site of the sequencing plasmic pUC-8 as two subclones, pT711 and pT106. DNA sequencing and hybridization studies showed that pT711 contains the pT17 sequence and an additional 172 upstream nucleotides. pT711 represents the coding sequence for the carboxyl half of the terminal transferase protein. pT106, containing a 965-base pair insert, hybridizes to the same mRNA as pT711 on Northern blots and contains an open reading frame that is in phase with the reading frame of the insert in pT711. Amino acid sequencing of the 58-kDa peptide of the calf thymus terminal transferase failed, indicating that the N terminus is blocked. N-Terminal sequencing of a 56-kDa form of the protein produced 24 amino acids corresponding to the translated human cDNA coding sequence starting at residue 398 of the insert in pT106 with 83% homology between bovine and human sequence. The initiation codon is assigned to an ATG sequence at nucleotide 329 of the insert in pT106. Comparison of the translated human terminal transferase sequence with peptides from the calf thymus enzyme showed that the homology between the human and bovine enzyme is better than 90% among 263 amino acids determined. The coding sequences in pT106 and pT711 were recloned into an expression plasmid pUC-19 downstream from the lac promoter and in phase with the coding sequence of the lac Z gene. Lysates of bacteria carrying the reconstructed coding sequence of human terminal transferase contain a fused protein of 60 kDa that reacts with rabbit antibody to terminal transferase on immunoblots and exhibits enzyme activity. Isolation of this fused protein from bacterial lysates with mouse monoclonal antibody to human terminal transferase produces the expected protein of 60 kDa.

Expression and processing of recombinant human terminal transferase in the baculovirus system.

Overproduction of human terminal transferase protein has now been accomplished by cloning the coding sequence of human terminal transferase into a baculovirus, where the expression of terminal transferase is under the control of the polyhedrin protein promoter. Two constructs were made, one producing a protein containing the entire terminal transferase fused to 12 amino acids from the NH2 terminus of the polyhedrin protein, and the other producing 58-kDa human terminal transferase. The terminal transferase levels expressed in cells infected with either recombinant baculovirus are around 10,000 units/10(7) cells at 48 h postinfection, about 200-fold greater than levels expressed in thymus and cultured lymphoblastoid cells. The chimeric polyhedrin/human terminal transferase protein produced in the infected insect cells has a molecular weight of about 60,000 while the nonfused recombinant human terminal transferase is identical in molecular weight to that present in human lymphoblastoid cells. Both forms of recombinant terminal transferase show immunological and enzymatic activity. When infected cells are pulse-labeled with [35S] methionine at 42-45 h postinfection, about 10% of newly synthesized protein is terminal transferase. Both forms of terminal transferase are phosphorylated in recombinant virus-infected cells as demonstrated by pulse-labeling infected cells with 32P-inorganic phosphate and isolation of labeled terminal transferase peptides by immunoprecipitation.

Vaginal Chlamydia trachomatis infection in children with sexual contact.

To determine whether vaginal infections with Chlamydia trachomatis in children were associated with sexual contact, 50 children ages 1 to 12 years with a history of sexual contact and 34 children without such a history were studied. Vaginal, throat and rectal cultures for C. trachomatis and Neisseria gonorrhoeae were performed in all children. Three children with sexual contact and none of the children without a history of sexual contact had vaginal infections. The three infected children were asymptomatic and only one had had vaginal intercourse. None of the 10 children with a history of sexual contact and gonorrheal vaginitis had C. trachomatis isolated. Although C. trachomatis vaginal infections as detected by vaginal cultures are infrequent, we recommend that all girls being evaluated for sexual contact be routinely cultured for C. trachomatis so that those infected can be treated.