Systematic reviews should incorporate as much relevant evidence as possible to reduce bias and research waste and increase reliability of results. Clinical trials registers are a key resource for identifying potentially eligible studies, particularly those that are unpublished, and therefore searching these registers is mandated for best practice systematic reviews. However, the process of searching can be challenging and no clear and consistent guidance on how best to do this exists. This paper provides step-by-step guidance on how to conduct systematic searches for studies using clinical trials registers, with a case study to illustrate each step. The guidance encompasses where to search and how to formulate the search strategy, conduct the search, download results, screen records, obtain data, update searches, and report on these searches.

CONTEXT: The International Liaison Committee on Resuscitation prioritized scientific review of umbilical cord management at term and late preterm birth. OBJECTIVE: To assess effects of umbilical cord management strategies (clamping timing and cord milking) in infants ≥34 weeks’ gestational age. DATA SOURCES: Cochrane Central Register of Controlled Trials, Medline, PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and trial registries searched July 2019. STUDY SELECTION: Two authors independently assessed eligibility of randomized controlled trials. DATA EXTRACTION: Two authors independently extracted data and assessed evidence certainty (Grading of Recommendations Assessment, Development and Evaluations). RESULTS: We identified 46 studies (9159 women and their infants) investigating 7 comparisons. Compared with early cord clamping (ECC) <30 seconds, delayed cord clamping (DCC) ≥30 seconds (33 studies), intact-cord milking (1 study), and cut-cord milking (2 studies) probably improve hematologic measures but may not affect survival without neurodisability, anemia in early infancy, or maternal postpartum hemorrhage. No differences in major neonatal morbidities are seen in studies comparing methods of optimizing placental transfusion (DCC versus cut-cord milking [3 studies], longer delays in clamping [7 studies], or physiologic parameters [3 studies]). Strategies that promote increased placental transfusion may be associated with greater phototherapy use. Evidence for all outcomes was low or very low certainty. LIMITATIONS: Incompleteness and low certainty of findings limit applicability. CONCLUSIONS: Compared with ECC, DCC or cord milking increases hemoglobin and hematocrit immediately after birth in infants ≥34 weeks’ gestational age. The uncertain effects of DCC and cord milking compared with ECC on major morbidities limit usefulness of available evidence for policy and practice.

In this protocol we describe the incorporation of bio-orthogonal amino acids as a versatile method for visualizing and identifying de novo-synthesized proteins in the roundworm Caenorhabditis elegans. This protocol contains directions on implementing three complementary types of analysis: 'click chemistry' followed by western blotting, click chemistry followed by immunofluorescence, and isobaric tags for relative and absolute quantification (iTRAQ) quantitative mass spectrometry. The detailed instructions provided herein enable researchers to investigate the de novo proteome, an analysis that is complicated by the fact that protein molecules are chemically identical to each other, regardless of the timing of their synthesis. Our protocol circumvents this limitation by identifying de novo-synthesized proteins via the incorporation of the chemically modifiable azidohomoalanine instead of the natural amino acid methionine in the nascent protein, followed by facilitating the visualization of the resulting labeled proteins in situ. It will therefore be an ideal tool for studying de novo protein synthesis in physiological and pathological processes including learning and memory. The protocol requires 10 d for worm growth, liquid culture and synchronization; 1-2 d for bio-orthogonal labeling; and, with regard to analysis, 3-4 d for western blotting, 5-6 d for immunofluorescence or ~3 weeks for mass spectrometry.