Writing Scientific Manuscripts

John P. Fisher, PhDJohn A. Jansen, DDS, PhD

Peter C. Johnson, MDAntonios G. Mikos, PhD

Co-Editors-in ChiefTissue Engineering Part A

Tissue Engineering Part B, ReviewsTissue Engineering Part C, Methods

Tissue Engineering and Regenerative Medicine International Society2016 Americas Meeting

San Diego, CADecember 14, 2016

Writing Scientific ManuscriptsOverview

• A primary task of science is the communication of technical results to the broader community

• Scientific communication is a critical step in the scientific method and is the key driver of advancement within a scientific field

• Therefore, the construction of a written scientific manuscript must be rigorously executed

Writing Scientific ManuscriptsOverview

• Successful manuscripts typically have three, strongly perfected components• The overall idea• The execution of the work• The presentation of the work

• While each of these is critical, the guidelines discussed here address the presentation of the work

• Concept must be innovative• Execution of the investigation must be thorough

Writing Scientific ManuscriptsObjective

• Describe a pertinent scientific question

• Then logically presents an answer to this question• The answer should be based upon theoretical or experimental results

• Clarity - in presentation and thought - should be the guiding principle

Writing Scientific ManuscriptsStructure and Approach

• Scientific research often begins with a defined research question, which results in a well designed research protocol that plans the overall approach

• Hypothesis driven• Innovation driven

• This foundation should lead to a set of data from which the manuscript can be constructed

Writing Scientific ManuscriptsStructure and Approach

• Manuscripts submitted to journals for consideration for publication typically have the following components

• Title Page• Abstract• Introduction• Methods• Results• Discussion• Conclusions• Acknowledgements• References• Tables and Table Captions• Figure and Figure Captions

Writing Scientific ManuscriptsStructure and Approach

• A reasonable approach to writing a scientific manuscript may be the following• Write the Methods section

• Derived from your initial research protocol• Construct all of the figures and tables that contain the data• Write the Results section• Write the Introduction section

• Define the scientific questions the manuscript will address• Refer to your research protocol

• Write the Discussion section• Use the Introduction and Results as guide

• State key points in Conclusions section• Summarize text in an Abstract

Writing Scientific ManuscriptsTitle Page

• State the title of the manuscript• Short and simple• Include “searchable” words

• Indicate authors and author affiliations

• Indicate the journal to which the manuscript is being submitted

• Provide approximately 5 key words

• State a short title (running title) for the manuscript

• Provide complete contact information for the corresponding author

Writing Scientific ManuscriptsAbstract

• Typically an independent, single paragraph

• Clearly state the objective of the experiment

• State the hypothesis

• Describe how the investigation was carried out

• Succinctly describe the results of the experiment

• End with a description of the significance of the work

Writing Scientific ManuscriptsIntroduction

• Begins with a short review of the literature• Best constructed as a descriptive funnel, starting with broad topics and

slowly focusing on the work at hand• Perhaps 3 – 4 paragraphs are needed

• The final paragraph then states• The experimental question• The hypothesis• The experimental approach• A summary on the contribution to the overall field of study

Writing Scientific ManuscriptsMethods

• A straightforward description of techniques• The use of the passive voice is probably appropriate• Each method should be described in a separate section

• Begin with a statement of the materials and indicated the vendor for each material

• Describe a specific experimental design or modeling component

• Next describe, in separate sections, each key technique• Keep explanations brief and concise

• Finally, describe the statistical analysis methods that were utilized

Writing Scientific ManuscriptsResults

• Present the experimental data to the reader• Be succinct and do not discuss or interpret the data

• The data itself should be presented in tables and figures (cited in text)

• Introduce each group of tables and figures in a separate paragraph • Note overall trends and data points of particular interest

• For experimental studies, state key statistics• Number of samples (n)• Index of central tendency (mean, median, or mode)• Index of dispersion (SD, SEM)• Significance of data (p value)

Writing Scientific ManuscriptsDiscussion

• The discussion section is often the most difficult to write• A well-defined study should ease the construction of the Discussion

• Refer to the last paragraph of the introduction• If the work has presented a hypothesis, use the results to construct a logical

argument that supports or rejects your hypothesis• If the work has identified three main objectives for the work, use the results to

address each of these objectives

Writing Scientific ManuscriptsDiscussion

• Begin with a brief paragraph that again gives an overview to the work

• Summarize the most important findings and, if applicable, accept or reject the proposed hypothesis

• Identify the most interesting, significant, remarkable findings and contrast these findings with literature

• Discuss the potential weaknesses of the interpretation

• Finally, consider the other relevant works in the literature

• State how this work contributes to the overall field of study

Writing Scientific ManuscriptsConclusions

• First introduce the work

• Briefly state the major results

• State the major points of the discussion

• State how the work contributes to the overall field of study

Writing Scientific ManuscriptsAcknowledgements

• Provide a brief statement acknowledging the efforts of any participants or consultants who are not included as authors of the manuscript

• State all of the funding sources for the work, ensuring that the statement adheres to the guidelines provided by the funding institution

Writing Scientific ManuscriptsReferences

• Include all references that have been cited in the text• Include all key sources in the field • Cite previous studies that support or motivate the present work• Do not include extraneous references in an effort to simply cite particular

authors or journals• It may be appropriate to cite previous publications from your own

laboratory, but this should be done judiciously.

• You must use the reference format that is mandated by the journal• Software packages make citing literature particularly easy

Writing Scientific ManuscriptsTables and Table Captions

• Included in a separate section after the References section

• Formatted so that the data is clearly presented and easily interpreted by the reviewer

• The table is likely to be reformatted by journal to conform to its standards

• All tables need a caption• Identify the table in bold and state a brief title• Include sentence that describes the content and impact

• Cite each table in the manuscript text

Table 1. Mechanical properties of PGLA-P(CL/LA) grafts and human vessels commonly used in autologous transplants. The fabricated PGLA-P(CL/LA) grafts possess mechanical properties in the range of normal human vessels.

Graft TypeBurst

Pressure(mmHg)

Modulus(MPa)

UltimateTensile

Strength(MPa)

Suture Retention Strength

(N)

PGLA w/ 10% P(CL/LA) 1002 + 181 17 + 3 2.9 + 0.3 2.2 + 0.4

PGLA w/ 15% P(CL/LA) 1321 + 214 27 + 6 4.5 + 0.9 3.2 + 0.5

Human Saphenous Vein 1680 to 2273 6.7 to 8.0 2.0 to 2.4 1.9 to 2.5

Human Femoral Artery 2031 to 4225 9.3 to 12.6 1 to 2 0.5 to 3.3

Writing Scientific ManuscriptsFigures and Figure Captions

• Placed in a separate section after the References section

• Clarity is the key factor• All images, plots, and legends should be as large and include legends• All images should include accurate scale bars

• All figures need a caption• Identify the figure in bold and state a brief title• Succinctly present the significant result or interpretation• For plots, state what the data point represents

• Data are means / Error bars are standard deviations

• Ensure that each figure is referred to in the manuscript text

Figure 1: Paradigms of Endothelialization of Vascular Grafts. ECs migrate from neighboring tissues over the anastomosis, while EPCs respond to functionalized vascular graft surfaces. ESPCs adopt a EC phenotype, under influence of shear stress, growth factors, and immobilization to the graft surface.

Figure 4. Comparison of Graft Mechanical Properties. Data indicates (A) ultimate tensile strength, (B) elastic modulus, (C) burst pressure, and (D) suture retention strength of 10% and 15% P(CL/LA) solution sealed PGLA grafts. Data are means ± standard deviation

Writing Scientific ManuscriptsAuthorship and Originality

• Plagiarism is unfortunately a major concern among editors and publishers• Protect your scientific reputation• Be certain of the sources of all data and text• Be sure to reference any prior work properly• An original research paper can not contain previously published data in any

form without a proper citation

• Authorship and the order of authorship must be agreed upon by all• Non-author personnel who contributed must be consulted

• It is not permissible to translate a previously published paper

Writing Scientific ManuscriptsSummary

• A scientific manuscript is meant to convey technical information to the reader• The technical aspect of the work is likely to require consideration by the

reader• The text should not further obscure the concepts and results

• Construct the manuscript with a straightforward presentation and discussion