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To determine the immunologic effects of oropharyngeal colostrum administration in extremely premature infants. METHODS:We conducted a double-blind, randomized, placebo-controlled trial involving 48 preterm infants born before 28 weeks' gestation. Subjects received 0.2 mL of their mother's colostrum or sterile water via oropharyngeal route every 3 hours for 3 days beginning at 48 to 96 hours of life. To measure concentrations of secretory immunoglobulin A, lactoferrin, and several immune substances, urine and saliva were obtained during the first 24 hours of life and at 8 and 15 days. Clinical data during hospitalization were collected.RESULTS: Urinary levels of secretory immunoglobulin A at 1 week (71.4 vs 26.5 ng/g creatinine, P = .04) and 2 weeks (233.8 vs 48.3 ng/g creatinine, P = .006), and lactoferrin at 1 week (3.5 vs 0.9 mg/g creatinine, P = .01) were significantly higher in colostrum group. Urine interleukin-1b level was significantly lower in colostrum group at 2 weeks (55.3 vs 91.8 mg/g creatinine, P = .01). Salivary transforming growth factor-b1 (39.2 vs 69.7 mg/mL, P = .03) and interleukin-8 (1.2 vs 4.9 ng/mL, P = .04) were significantly lower at 2 weeks in colostrum group. A significant reduction in the incidence of clinical sepsis was noted in colostrum group (50% vs 92%, P = .003).CONCLUSIONS: This study suggests that oropharyngeal administration of colostrum may decrease clinical sepsis, inhibit secretion of pro-inflammatory cytokines, and increase levels of circulating immune-protective factors in extremely premature infants. Larger studies to confirm these findings are warranted. WHAT'S KNOWN ON THIS SUBJECT:Immunerelated bioactive proteins are highly concentrated in the colostrum of mothers who deliver preterm infants. Oropharyngeal administration was proposed as a safe and feasible alternative method of providing colostrum to immunocompromised premature infants. WHAT THIS STUDY ADDS:Oropharyngeally administered colostrum during the first few days of life increased urinary secretory immunoglobulin A and lactoferrin, decreased urinary interleukin-1b, reduced salivary transforming growth factor-b1 and interleukin-8, and reduced the occurrence of clinical sepsis in extremely premature infants.

The edge-to-face interactions for either axially or facially substituted benzenes are investigated by using ab initio calculations. The predicted maximum energy difference between substituted and unsubstituted systems is approximately 0.7 kcal/mol (approximately 1.2 kcal/mol if substituents are on both axially and facially substituted positions). In the case of axially substituted aromatic systems, the electron density at the para position is an important stabilizing factor, and thus the stabilization/destabilization by substitution is highly correlated to the electrostatic energy. This results in its subsequent correlation with the polarization and charge transfer. Thus, the stabilization/destabilization by substitution is represented by the sum of electrostatic energy and induction energy. On the other hand, the facially substituted aromatic system depends on not only the electron-donating ability responsible for the electrostatic energy but also the dispersion interaction and exchange repulsion. Although the dispersion energy is the most dominating interaction in both axial and facial substitutions, it is almost canceled by the exchange repulsion in the axial substitution, whereas in the facial substitution, together with the exchange repulsion it augments the electrostatic energy. The systems with electron-accepting substituents (NO2, CN, Br, Cl, F) favor the axial substituent conformation, while those with electron-donating substituents (NH2, CH3, OH) favor the facial substituent conformation. The interactions for the T-shape complex systems of an aromatic ring with other counterpart such as H2, H2O, HCl, and HF are also studied.

We report the growth of ultralong (>10 cm) multi-walled and single-walled carbon nanotubes such that the length is limited by the size of the furnace rather than by the termination of growth. The disturbance of microscale laminar flows results in disordered or shorter growth of carbon nanotubes. By downsizing reaction pipes, reaction gas flows are stabilized with low Reynolds numbers. In this way, the catalyst nanoparticles at the end of growing carbon nanotubes can travel a longer distance to grow ultralong nanotubes.

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The construction of catenanes, comprised of between two and seven interlocked rings, has been achieved. Two tris-1,5-naphtho-57-crown-15 macrocycles template the formation of cyclobis(paraquat-4,4′biphenylene) to give a [3]catenane, which acts as a template for the construction of one and then another cyclobis(paraquat-p-phenylene) to give a [4]-and [5]catenane (Olympiadane). When high pressure was used in these templated syntheses, a [6]-and [7]catenane, as well as a [5]catenane that is topologically isomeric with Olympiadane, were also obtained. X-ray analyses of the [3]-, [5]-, and [7]catenanes reveal an optimum use of electrostatic, π-π stacking, [C-H‚‚‚π] interactions, and [C-H‚‚‚O] hydrogen bonds in the organization of the component rings within the molecules. Noteworthy in the [7]catenane structure is the location of four of the PF 6anions within voids present in the 20 + ion. Temperature-dependent 1 H NMR spectroscopic studies and electrochemical investigations have revealed the dynamic and redox behavior of these catenanes in solution.