Contents 1. Introduction 3943 2. Experimental Techniques Available for the Study of Molecular Clusters 3945 2.1. IR Spectroscopy 3945 2.2. UV Spectroscopy 3946 2.3. Cluster Cations 3946 2.4. Cluster Anions 3946 2.5. Real-Time Monitoring of Solute−Solvent Interactions 3947 3. Problems Specific to the Study of Molecules of Biological Interest in the Gas Phase 3948 3.1. Production and Ionization of Molecules of Biological Interest in the Gas Phase 3949 3.2. Determination of Biomolecule Structures in the Gas Phase 3949 3.3. Microwave, Optical, and RET Spectroscopies of Molecular Clusters of Biological Interest in the Gas Phase 3950 4. Case Studies 3950 4.1. DNA Base Complexes 3950 4.1.1. Isolated Base Pairs 3951 4.1.2. Influence of Solvation upon Ionization Potentials and Electron Affinities of Nucleobases 3952 4.1.3. Proton Transfer and Tautomerization of Nucleobases and Related Molecular Systems 3953 4.2. Peptide Bonds and Amino Acid Side Chains 3953 4.2.1. Models of Peptide Bonds 3953 4.2.2. Models of Amino Acid Residues 3954 4.2.3. Disulfur Bonds 3954 4.2.4. Zwitterions 3954 4.3. Nucleobase−Amino Acid Residue Interactions 3955 4.4. Influence of Methylation 3956 4.5. Modeling of Hydrophobic Interactions 3957 4.6. Chiral Clusters 3957 5. Conclusion 3958 6. References 3959

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The influence of N-methylation on the dipole-bound electron affinities of pyrimidine nucleic acid bases, uracil and thymine, has been investigated theoretically using ab initio quantum mechanical calculations, and experimentally using Rydberg electron transfer spectroscopy. Both experiment and theory are consistent in showing that replacement of hydrogen atoms by methyl groups reduces electron affinities corresponding to formation of dipole-bound anions of these systems. Also, the distortion of the anion geometries with respect to the geometries of the neutral parents are reduced with the methylation.

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By means of Rydberg electron-transfer spectroscopy (RETS), negative ion photoelectron spectroscopy (NIPES), and quantum chemistry calculations, we have studied electron attachment properties of a series of saturated disulfides: dimethyl disulfide, diethyl disulfide, and dipropyl disulfide. Both RETS and NIPES experiments show that the valence anions of these disulfides are stable. RETS further shows that these negative ions result from attachment of nonzero energy electrons (0.2 eV), in contrast to dimers and larger complexes. NIPES experiments provide vertical detachment energies for the three disulfide monomer anions along with their Franck-Condon profiles. Fitting these spectra, using model potentials for the S-S stretch coordinate, finds that the adiabatic electron affinities of these disulfides are positive but rather small, about 0.1 eV. These experimental data compare well with the results of ab initio calculations, performed at the MP2 level with large basis sets.

We highlighted associations between gestational exposure to some phthalates and growth in boys. The positive association between MEP and postnatal growth in boys was also reported in several previous human studies.

We present both experimental and theoretical gas-phase studies of several noncovalent complexes of elementary molecules of biological interest:  adenine, imidazole, pyrrole, and water. By means of charge-transfer collisions between those complexes and laser-excited atoms, dipole-bound cluster anions are observed. This Rydberg electron transfer (RET) spectroscopic technique is used to experimentally determine the very weak excess electron binding energies of the complex anions. Theoretical calculations which rely on a homemade semiempirical intermolecular force field allow for the determination of the structures of the low-lying equilibrium configurations of the neutral complexes. The electrostatic properties of these configurations (dipole moments, quadrupole moments, etc.) lead to predicted excess electron binding energies which are compared to the experimental values. This comparison provides a test of the validity of the employed methods, as discussed in the case of the five studied complexes: adenine−imidazole, adenine−pyrrole, adenine−water, pyrrole−water, and imidazole−water.

Background In 2014, the government of Togo implemented a pilot unconditional cash transfer (UCT) program in rural villages that aimed at improving children’s nutrition, health, and protection. It combined monthly UCTs (approximately US$8.40 /month) with a package of community activities (including behavior change communication [BCC] sessions, home visits, and integrated community case management of childhood illnesses and acute malnutrition [ICCM-Nut]) delivered to mother–child pairs during the first “1,000 days” of life. We primarily investigated program impact at population level on children’s height-for-age z-scores (HAZs) and secondarily on stunting (HAZ < −2) and intermediary outcomes including household’s food insecurity, mother–child pairs’ diet and health, delivery in a health facility and low birth weight (LBW), women’s knowledge, and physical intimate partner violence (IPV). Methods and findings We implemented a parallel-cluster–randomized controlled trial, in which 162 villages were randomized into either an intervention arm (UCTs + package of community activities, n = 82) or a control arm (package of community activities only, n = 80). Two different representative samples of children aged 6–29 months and their mothers were surveyed in each arm, one before the intervention in 2014 (control: n = 1,301, intervention: n = 1,357), the other 2 years afterwards in 2016 (control: n = 996, intervention: n = 1,035). Difference-in-differences (DD) estimates of impact were calculated, adjusting for clustering. Children’s average age was 17.4 (± 0.24 SE) months in the control arm and 17.6 (± 0.19 SE) months in the intervention arm at baseline. UCTs had a protective effect on HAZ (DD = +0.25 z-scores, 95% confidence interval [CI]: 0.01–0.50, p = 0.039), which deteriorated in the control arm while remaining stable in the intervention arm, but had no impact on stunting (DD = −6.2 percentage points [pp], relative odds ratio [ROR]: 0.74, 95% CI: 0.51–1.06, p = 0.097). UCTs positively impacted both mothers’ and children’s (18–23 months) consumption of animal source foods (ASFs) (respectively, DD = +4.5 pp, ROR: 2.24, 95% CI: 1.09–4.61, p = 0.029 and DD = +9.1 pp, ROR: 2.65, 95% CI: 1.01–6.98, p = 0.048) and household food insecurity (DD = −10.7 pp, ROR: 0.63, 95% CI: 0.43–0.91, p = 0.016). UCTs did not impact on reported child morbidity 2 week’s prior to report (DD = −3.5 pp, ROR: 0.80, 95% CI: 0.56–1.14, p = 0.214) but reduced the financial barrier to seeking healthcare for sick children (DD = −26.4 pp, ROR: 0.23, 95% CI: 0.08–0.66, p = 0.006). Women who received cash had higher odds of delivering in a health facility (DD = +10.6 pp, ROR: 1.53, 95% CI: 1.10–2.13, p = 0.012) and lower odds of giving birth to babies with birth weights (BWs) <2,500 g (DD = −11.8, ROR: 0.29, 95% CI: 0.10–0.82, p = 0.020). Positive effects were also found on women’s knowledge (DD = +14.8, ROR: 1.86, 95% CI: 1.32–2.62, p < 0.001) and physical IPV (DD = −7.9 pp, ROR: 0.60, 95% CI: 0.36–0.99, p = 0.048). Study limitations included the short evaluation period (24 months) and the low coverage of UCTs, which might have reduced the program’s impact. Conclusions UCTs targeting the first “1,000 days” had a protective effect on child’s linear growth in rural areas of Togo. Their simultaneous positive effects on various immediate, underlying, and basic causes of malnutrition certainly contributed to this ultimate impact. The positive impacts observed on pregnancy- and birth-related outcomes call for further attention to the conception period in nutrition-sensitive programs. Trial registration ISRCTN Registry ISRCTN83330970.