?? symbols in annotations

[nakumgaurav]

Hi,

I am annotating a bunch of articles (ACS SynBio) using huner. For the most part, the results make sense but for some files, there are "?" symbols in annotations. You can have a look at a sample paragraph and its annotations:

The columns were maintained at 40 °C; 0.1% formic acid in acetonitrile (eluent A) and in water (eluent B) were used as eluents with the flow rate of 0.5 mL min –1 as follows: 0–1.5 min, 95% A, 5% B; 1.5–7.0 min, decrease 16.9% min –1 A, increase 16.9% min –1 B; 7.0–9.0 min, 2% A, 98% B; 9.0–9.1 min, increase 15.5% s –1 A, decrease 15.5% s –1 B; 9.1–11.5 min, 95% A, 5% B. Injection volume of 2 μm was used for the analytes. Absorbance was measured with a UV/vis detector at 600 nm. Analysis of Orthogonal Activators The functionality of each sTF and orthogonality in S. cerevisiae was tested by fluorescence measurements. The experiments were initiated by pre-cultivating S. cerevisiae cells (strains marked with asterisk in the column “Analysis of orthogonal activators” in the file) at 30 °C on YPD plates for 24 h. Four ml of SCD-UL medium in 24-well plate was inoculated to initial optical density of 0.2 (OD 600 ) by the pre-culture. Three parallel replicates were cultivated for each strain. Cells were cultivated 18 h at 28 °C, 800 rpm. Fluorescence was measured as described in the “ ” section. In addition to the fluorescence measurements, transcription analysis was performed for the subset of the strains. Strains containing sTF and Venus expression cassettes either with 2 or 8 sTF binding sites (strains H4623, ...

the annotations for which (from "acetontrile" in first line to "H4623") are:

acetonitrile
2 ? ?m
? ? ? ? ? ?
H4623

Also, some useful entities have "?" symbols between their tokens, such as "E. ?? coli membrane". Not that it is a significant issue since I can skip over the entities which containe such erroneous symbols (or regex parse them) but it would be helpful to know why it happens. Thanks!